EPTYou had him down to 7 drones and no queens, and no minerals in the bank. The game is effectively over at this point (or it should be)- you should know how many drones you have killed, roughly how many drones he could possibly have at that point, how many lings he's built, etc. You also know he has 4 spine crawlers and is sitting on his back foot because he's worried about whatever force you're going to followup with- so he's probably building zerglings too. You need to get to the point where thinking about how badly you've hurt him is automatic, and more importantly, where you stand relative to him.
After you saw the massive amounts of spine crawlers, I would have immediately withdrawn and expanded, and started pumping out sentries while teching to colossi. You're already ahead economically at this point- not by much, but once the expansion goes down and you've been chronoboosting probes out like a mad man, you will be. It worked out in your favor that you didn't, because the runby did way more damage and would have set you up for the easy win if you knew what to do.
However, you kept trying to pressure him after the runby when there wasn't any point in doing so, spending a lot of minerals that could have been spent on teching or more expansions. Your expansion timing was okay given the circumstances- what was not okay was missing a lot of chronoboosts and a few probe building cycles. Also- I suggest maynarding your probes to your expansion (ie, if you have 30 probes on minerals, move 15 to your expansion when the Nexus finishes- the difference in worker saturation means a huge boost income even with the time lost from mining). If you keep up with the chronoboosts, this will generally give you an instant (although transient) income lead on the Zerg in a more normal situation.
You built too many zealots again... most of those are going to die to roaches before they even get a hit in... furthermore, the amount of sentries you built considering your zealot numbers was highly excessive. In general, you do not want to get anymore sentries than is necessary (this depends on preference to some extent)- they don't do much damage, and they suck up 100 gas each. Get them early, and then build up energy on them, and then only build more if you need to.
To put your army in perspective this is what you both had before the first big fight:
16 zealots
6 colossi
11 stalkers
10 sentries
only +1 attack
vs
48 roaches
7 corruptors
Those 16 zealots are all going to die to roaches pretty much instantly... think about it. 48*16=768 damage. Ignoring armor, your zealots are all dead in roughly 3 roach attacks. How much damage did they do? No where near that, especially if you forcefield to block the roaches from encroaching on your colossi (and given you had 10 sentries, you almost had as many melee prohibiting units as melee units!). You get rid of 5 sentries that frees up 500 gas, which is 10 stalkers. Get rid of 2 colossi and all of your zealots could be stalkers. You now have a force of 27 stalkers, 4 collosi, and 5 sentries- if you forcefield properly and guardian shield, very few of your stalkers are going to die, and they do enough damage to one shot corruptors (pretty big deal, especially if you forcefield well since you can focus fire corruptors).
Your forcefields need work- I think you were conflicted between preventing them from getting too close and letting your zealots be able to attack. Don't get zealots, and don't let those roaches anywhere near your army- 48 roaches is a crap ton of roaches.
After that, none of it really matters- he's already got a massive lead, even after you sniped the hatchery. Killing drones is waaay more important. You let all but 1 of them escape!
So in summary you need to:
1. Have a better handle on the economic situation.
2. Exploit the economic situation when you can- expand! Chronoboost probes! Chronoboost upgrades! +3 attack is absolutely critical!
3. Work on your army composition some more- stalker/colossi/sentry should be the bulk of your army right around when the first massive battle breaks out. Only build zealots if the amount of zerglings forces you to or you have lot of extra minerals (even then- think twice about it, you could be expanding!).
4. Use your sentries more effectively- forcefield to prevent roaches from doing damage to your army, guardian shield to block more damage, and if you have the energy, to cut off his army from retreating (worry about this last, because if you do the other two things well, this probably won't even matter).
