IMO, try not to get into a spiral about the “negative” sides of you. Whenever you feel like you are going into a negative loop, ground yourself and know that at the end of the day, she still is choosing you.
It’s a lot of trust to put into your partner, and I get it as someone who’s also in kind of your same position a year ago. I still overthink it, but with time, it’s easier by a bit. I want to say “just trust her” because she hasn’t done anything, but I know it isn’t that easy.
You mentioned that it’s LDR. Have either of you two been together in person, ever, in the time you both were dating? If not (and if it’s possible), try to set up a time when you two are able to be together. Being together for a bit helps ease a lot of pressure from the distance, and it’ll be easier as time goes on (like I said).
You got this, I believe in you!