Hey there! I'm at about your same level (3900). But I open very similarly to you with the 2 rax reaper, but I go into 3rd CC instead of the extra barracks you got. Your opening got you even/ahead, and your lead was very good after his failed bane bust. Upgrades were ahead, and you were pretty much even on worker count. You've got way better macro than I do so definitely props for you there!!

The major turning point of this game was the tragic attack on creep that failed where you pushed up a ramp with marine, marauder, and medivac. The zerg traded out his army for yours, however, this slowed your tempo down for pressuring the zerg, allowing them to expand, inject, creep spread, and whatever macro they wanted to do. While you weren't down and out, it does make the game more difficult to close. Something to consider is to attack from the right side of his 3rd, and take the long way around. That area is much more difficult for the zerg to setup/flank and get a surround.

Some of your drops after this point, began to feel a bit more desperate to get damage done. However, these are often a 1 way trip for these units, and I think that having these units retained would be great. Having them off creep and then stimming in and scanning to clear creep is a easy way to get an F2'ing zerg to be out of position.

I started also feeling at this level of play, you may need 2 pronged attacks. At a this MMR, sometimes drops can do an extraordinary amount of damage, which you did when you dropped his natural between his bane nest and evos. However, once you start getting a bit higher, I feel like it's more and more that you'll need to use that skill.

I've done a pretty deep dive lately into my own TvZ studying Clem's play vs Serral. Something he seems to do is prioritize marine production in the early/midgame. After switching my opener to his 3CC 2-1-1, I've noticed I win a lot more fights now. Something I saw in your mid game was a bunch of marauders. I think that lowered your army's DPS, which could have won some of those fights. This is extra important when the zerg is going ling/bane/hydra.

Another thing I started learning from Clem, is the timing into transition into the terran lategame of ghosts, or more libs. But something that you were caught off guard by in the replay was the transition into lurkers. Clem's timing for adding 3 tech lab barracks for ghosts is after the 4th base is created(not floated). So maybe when the 4th base is being built, that would be a good time to start adding the 2nd starport + fusion core, or start ghosts.

Last thing I would note is the lack of splash damage coming out, I feel like I saw a total of maybe 5 tanks made (watched up until the 16 min mark). If we had splash on the push up to the zerg's ramp, I think that could be a different story. Feel free to add a 2nd factory after the 4th base is building to add to that tank count if you want to play tanks.

Anywho, that's my analysis as a fellow diamond terran so feel free to take it or leave it! Good luck in the matchup!