TvP axiom build order

For 2 gate zealot openings, it is hard to defend. The first thing we have to make sure is that we have a barracks and a supply depot touching the right hand side of the barracks. Marines can fit through the gap but zealots cant. This wall is inside our main base, near the top of the ramp. The depot wants to not be in the way for future factory placement ideally.
The most important thing is dont let the initial marines die. Sounds stupid I know. But so many pros get greedy and try to get extra shots in but end up losing the initial marines 1 by 1. Its critical to simply keep them alive while their numbers build up. Once you have 3 marines you are far far safer. Keep making marines non stop for this period, dont stop after 4. Stop when you have 8 and replenish back up to 8 if any die.
To fend off the initial zealots, use 4-6 scv.
Infact if you scout just a single zealot, I recommend putting 4 scv on your ramp to prevent the 1st zealot even getting into the main. The zealot might still get in but will have taken some damage to get up the ramp and its worth it. Some pros do this occasionally, its a bit overkill but I actually think its a very acceptable move and certainly worth it in our case. Once he has 2 zealots in your main use 6 scv (up to 8) to really get the situation under control. We just wanna clean them out of the main as a priority but keep/put 1 marine in the bunker and maybe 2 scv on the ramp to stop anymore zealots or the first goon from getting into the main too easily. Constant marine production, let the numbers build while the scvs try to screen and trap zealots.

You mention the zealots are killing the bunker. This suggests the protoss is probably letting his zealot number grow before sending all at once in a slightly delayed attack. The scv scouts should be informing you that he is making zealots. And the lack of goon pressure also is a clue. This is a perfect situation to switch the build from 1 tank 4 vult and instead go into the 8 marine pure tank variation. If we have extra marines when his zealots hit, terran will hold easily. Again, the scv scouts should be able to see this attack coming and give time to get scv in place to block and repair the bunker. Have 3-4 scv at the bunker ready to start repairing by this point anyway even if the bunker isnt taking any damage (he might be about to step in with 6 goons at once). If we know he is one base then all we have to do is hold. The priority is protecting the bunker and first tank with scvs.
If the zealots come in and you dont have scv ready to repair, you should still be able to hold though. Pull all the scv from the nat and get stuck in, get the marines back behind them if possible (but it might not be so just let them shoot instead if so). Lift the nat cc and float it towards the main if needed. If the zealots are able to penetrate you must pull the scv back to the main ramp and focus on blocking it so that the 1st tank is safe. You are still miles ahead by the way even if the nat cc lifts. Once his attack peters out, just reland the nat cc and re sim city the nat and continue the build. Be ready to switch into a 2 base 4 fac attack and go kill him.

I know it can go so horribly wrong though. Zealots are a pain in the ass. Here is terran losing, Sea vs Jangbi Ground Zero
http://www.teamliquid.net/tlpd/korean/games/96215_JangBi_vs_Sea/vod

At 5.41 in the vod, Sea is in a great position, he has killed the first zealot and his bunker is nearly done. The 2nd and 3rd zealot come in though and snipe a couple of marines. He needed to instead just run them away into his main, pull a couple of scv, and when his 4th marine pops run it away to the bunker. A bad situation we sometimes see is when Terran seems to be holding well and has 3 marines alive. However they are all on 1 hit and the next zealot comes along. The terran tries to get fancy and engages without scvs and it just often quickly goes sour for Terran. All 3 marines get killed by the zealot, 1 hit on each and suddenly there is no DPS to put inside the bunker etc. Gotta save those marines. A method you can employ that is a bit strange is when a marine is down to 1 hit, pretend like it is dead and you cant use it anymore, so micro it to a safe zone far from the action. Continue playing and then a few moments later suddenly you have an ‘extra’ couple of marines in your pocket which is often much more useful than if you had continued fighting with them, because all that would have happened is they get 1 small weak gauss rifle shot off before dying.

I should mention walling. Many terrans will recommend you wall at the nat with first (or second) depot and build rax at the nat too to form a zealot tight wall with the cc (when doing rax expo).
I prefer the style where you depot, rax, depot all in your main, then make cc at the nat, then float the rax to the nat. Its kind of boring and we go round and round in circles on this subject. There are much more interesting things to talk about. But then again, its early game, and this is the most important stage in some ways. So if someone desperately wants to talk about it we can ofcourse. So the first depot is built near the main cc (below and 1 tile gap). The rax is built near the main ramp but not too far from the main cc and the second depot is built touching the rax on the right hand edge. Cc is built at the nat. The potential problems are:
-proximity 2 gate zealot
-proximity 1 gate zealot
-1 gate zealot from a gateway built at the protoss nat
-continuous zealot from standard (in main) 1 gate (that’s 3,4 or more zealots)
http://www.teamliquid.net/forum/bw-strategy/417974-pvt-opening-3-zealot-cyber-core

Walling at the nat has a vulnerability vs proxy gates which Protoss can exploit and develop into a win (a bit too consistently for my liking). For me it’s a bit too much of a weakness such that I recommend an alternative. Some people say well Protoss doesn’t do proxy gates very often so it’s a risk worth taking. It’s a legitimate argument but I prefer builds that don’t rely on such things.
Walling at the nat is ok vs continuous zealots (be it from gate in the main or gate at the nat). So that’s a plus point for it just about.

Making depot rax depot in the terran main is a bit better vs proxy gates. For me its just enough over 50% consistently reliable to recommend (I dunno lets say its 65% while walling at the nat would be 40% or something). By no means is it easy (no build is though). This style is a bit harder to establish your nat cc though. A single zealot is not too hard to deal with for pros. 2 zealots can be a bit annoying but normally pros handle that just fine. 3 or more is when it starts getting irritating. Its tricky, it’s a problem, but it is possible to defend.
I guess the last thing to mention is that a bot might be able to go cc first every game even on 2 player maps and always win with superior micro one day.