I can relate 100%

I know exactly how you feel, believe me. It's like the idea just gets injected at light speed into your current train of thought, even if it has nothing to do with what's happening. For me, this includes "I should just die", "I'm gonna hang myself", and the almost ever-present "I hate myself", which sometimes come out audibly. It's pretty distressing because it's almost like I'm not the one making myself say/feel these things. I've even been to the point where I've held an actual firearm to my head and thought "If this were the way I chose... this would be the last thing I saw and felt" and meditated on that for a bit.

This is hard because I don't have much advice on how to deal with it as I don't quite have a grasp on that yet myself. All i can say is try to find something to occupy your time, i suppose. Never underestimate the power of the company of a good friend (even if you can't talk to them about your attraction), though as an extremely introverted individual I sometimes find it hard to take this advice. Find some music that strikes you in a brilliant way, sit in the sun, take a walk. It can be hard to battle bad thoughts when they specialize in sneak attacks, but there are many things you can do to keep them at bay. As someone who feels the same way as you, I know this to be true.