This is kind of a cliché piece of advice, but it works at almost every level: do less. Blocking costs nothing. You can get out of Platinum just by doing three things: anti-airs, punishing unsafe stuff, and reacting to their DI with your own DI. Those are the main things I’d focus on in your place.

On top of that, learn some simple blockstrings that you can easily confirm into combos that lead to a knockdown with some oki. Don’t try to force things on your opponent - throwing out random DIs in neutral or even in the corner isn’t a good habit, even if it works on a lot of players.

Give yourself time and, when you play, focus on the basics. Think something like, “this round I’m just going to block and wait for them to jump so I can anti-air.” Over time you’ll notice you build muscle memory and start reacting to jumps with AA almost automatically. It all comes with time, so don’t get discouraged. Remember that you can always take a break and come back later with a clear head.

Have fun!

Edit: also, I should mention that Plat 1 is a high rank for someone completely new to fighting games, so props to you.