Hello Wafflelisk
I watched your replay and think I can help you out a bit
To be honest I think you opened very well against what he did, taking that third was an excellent response to his Forge Fast Expand, but shortly after that is where I think the problems started.
You scouted that he had taken his 3rd at 7:40, and I think you saw that as an opening to attack. On some maps this could be a viable option, but one thing that this seasons map pool does not have is many thirds with an open entrance. As ZvP one of the main rule of engagements is to avoid chokes unless they are beneficial to you, because force fields can split your army into half and next thing you know you have nothing.
Maybe if you didn't take your third and went got out another 20 lings or 4-5 roaches on 2 base, then perhaps you could of taken out his third by having so many more units than him, but half-expanding and half-attacking kind of put you in a weird position.
And just to note, between the attack on P's third and his blink attack at your natural, about 21 roaches were lost and 1 stalker, mainly due to splitting up your army and not having map vision.
In that situation I would of expanded to my 4th right as I saw his 3rd go down, he took his 3rd so early that you know he wont be able to push for another few minutes at least, so you have a fairly safe window to drone up as well.
If you had not attacked, taken your 4th earlier, and scouted a bit more I think you would of been in much of a better situation.
Aside for that, there were some other things to consider, for instance I noticed you never upgraded Grooved Spines (Hydra Range), and a good composition tip in the future is that you want about a 1:1 ratio of roach to hydralisk. Hydralisks eat gateway units for breakfast, but they are really squishy as well. The roach serves as the tank in the comp so that the hydras can do damage, and when you have 8 roaches and 15 hydralisks against 29 stalkers, even though you were in a small upgrade advantage you died so fast because you had no meat shield. Lastly, make sure you have infestors with your army because the area of effect damage from fungals plus the hydralisk dps dissolves mass stalker comps.
I hope this advice is helpful, i'm only in silver league but I think I understand the ZvP match up pretty well.
Good luck in future games.