How do I let go?

So I’m a natural squeezer. I squeeze on high notes. Low notes. Basically every note. Even when I’m alone, I feel confident in my brain. But when I hit I note I’ll tense up. I have no clue how to trust myself. But at the same time it’s not a confidence problem but it is. I think I used to be so uncomfortable that I’ve carried those nonconfident traits over to my singing now. But I can’t break those habits. I don’t know how to pull an Elsa and let it go. It’s weird. Cause I feel confident when going for a note…then I’ll tense anyway and I get frustrated. Any tips to break this bad habit of squeezing.