ill try to give some tips from what i seen in the replay:

1) expo faster, getting an expo greatly increases your income, if your not doing an all in or getting a specific tech you generally want to expand as fast as possible(and be safe) generally, especially when your just massing up units your better of getting your expo faster and after that adding more production facilities so you can mass those units alot faster, also you dont need a double gas if you dont plan to tech quickly, especially not if you intend to build a just large number of helions and marines(as opposed to getting siege tanks/medivacs/ banshees out quickly). instead of all that gas you mined but not used till way later could have been used to put up an expo way earlier and then got more gasses as your about to start producing thors/tanks/medivacs/upgrades
(and if your afraid of expoing just make the cc in your base while making some bunkers at your expo before you transport it).

2) transfer workers to your expo, above 2 workers a patch(16) the mining efficiency of extra workers greatly diminishes.

3) make orbitals out of your cc's as fast as possible(and hotkey them in a group so you can use all the mules), as the money from the extra mules is better then the extra svcs you build in that time

4) when you engage you often are just moving without shooting, if you dont have the apm to miro properly just a +click on the ground just behind your enemys also when moving around the map a move where you are going to so your units attack the moment they get in range instead after the lings start hitting them

5) biggest problem i think was his 3 base economy to your 1.5(barely) base economy, take more expansions, and make sure they are saturated with workers(that is getting near 16 workers on minerals)

6) vs mass mass muta you gonna want some thors to support your marines vs the mutas(as their long anti air range can cover alot of area and they do splash damage, wich either wrecks the whole muta ball if he clumps off or forces him to magic box(a technique that makes sure they keep spread out) but magic boxed mutas are alot less effective vs marines then a really clumped up muta ball).
7) upgrade your marines vs enemy units without armor a weapon upgrade increases the dps output with about 20 percent, a stimmed 3/3 marine with shields upgrade beats 2 marines without upgrades

8) you only had 1 baracks without reactor building marines and all your factorys where building tanks wich werent even covering your marines from the zerglings when you fought with him, either make more rax(get stim and shields also) or produce thors, as 1 rax worth of aa just is never going to be enough(3 is more appropriate).
1 muta is more expensive then 6 marines, i am not sure you even had 2 marines for each mutalisk, so he spend alot more resources on his air then you invested in your anti air.