I am so frustrated with myself right now. I have lots of work right now which is giving me a lot of stress, and I don't get to see my s.o. much (once every week or two - we've been together about 1 year)... Every time i DO see her, I always just get angry at her but I don't know why

I can't do this because it's frustrating for her, and I am going to destroy a relationship with one of the most amazing women I've ever known.
I seriously can't control myself, and I really don't understand how I can do this to someone I love. It's not really a reason to get angry, but I always feel that when we are together she has something better to do than spend time with me, and these thoughts just set me off to being untrusting, angry, and/or jealous of her (part of this feeling stems from her loss of passion in the relationship).
Agh, I just don't know how to explain myself to her, and worst of all I have a fear she won't put up with me and will find someone else. How can I stop myself on a course of self-destruction? And how do I tell her this?