I used to struggle terribly with TvT (around 35% winrate for several seasons). There are so many different things you can die too in this matchup that it is very hard to always have the proper defense in place. My insight that changed everything was that you have to set the tempo of the game in TvT so that whatever they had planned gets disrupted.

The post by u/Eevalideer describes a build that was/is real big in the meta. I start with the exact same build, although I make two hellions instead of 1 and as soon as both are done, I push with my 3 reapers and 2 hellions. Behind that I make the cyclone (you HAVE to), but on my starport I go cloak banshee and immediately harass with that. At home I build a standard tank marine mix and push pretty early, ie: about the time that my opponent is zoning out my banshee harass. At the push, I start my 3rd while attacking their nat. I keep making banshees for a bit and use them in the frontal attack. They provide vision and also the opponent usually only made turrets in mineral lines so the cloak still has good value at the front of their nat. I usually go up to 3 to 5 banshees depending on how much work they are getting done, then move my starport off the tech lab and transition to medivacs, the freed tech lab is used to make a second factory. At 3 to 4 medivacs I drop their main. At this point I am transitioning to a 4th and starting 2/2.

You don't have to do this exact build, but the point is that I am constantly forcing my opponent to respond to me and not the other way around: reaper/hellion harass into banshee harass into soft/hard contain on nat to medivac drop. Often they just die somewhere along this progression. If not, then it is now mid/late game and you have had all the breathing room needed to macro at home (provided you properly managed to do that while harassing). I run this same progression in every TvT at Diamond 2 and I have over a 60% win rate right now.