ashamed

I've been in abusive relationships in the past. I grew up with a cheating dad and an alchoholic mom. I feel like I don't even know what a "normal" relationship is. My husband and I had a wonderful start. We never argued. But the stress of life started causing arguements. When he's stressed out he gets mad at everything. But I know I get snippy when I'm mad too. I feel horrible. I'm afraid our new marriage is already falling apart. We have an amazing few days then we have a huge blowout fight. I don't even know if it's me or him or both of us. Part of me says the reason my relationships go to shit is because I just suck at this whole life thing. My husband has done some very hurtful things. But he has also been the best to me that anyone has ever been. He's such a good person, truly, and he never intends to hurt my feelings. But he has his communication issues too, from having a rough family life. We are so alike it hurts us. Lately I just feel like I can't do anything right and I keep resorting back to my self harming behaviors from my past. Not wanting to eat, scratching myself up when I can't take it, smoking a whole pack of cigarettes within hours. He knows how I feel. But we both just blame each other. We agree to work harder then we fight again. I don't know what's wrong with me. What can I do to fix this marriage before it falls apart only months in? How do I convince myself that I'm not worthless so I can build myself back up instead of tearing myself down? Please no judgement. I really need love and advice right now.