Physical Outburst and Forgiving Oneself

I had a major fight with my boyfriend today. I couldn't find my keys and he scolded me on not putting them in the right place. I started to get more and more angry and asked him to leave. He wouldn't, saying that I had to learn deal with my emotions. Then my borderline rage came out and I threw my cell phone across the room which got him really angry and he told me that I'd never get better. (I've been in therapy for 20 years). Well, the point is that I lost it....and all my DBT skills went out the window and I kicked a chair at him and hit him several times. This is like the fourth physical argument I've had with him. It has been over five years since something like this has happened. Once I realized what I was doing I ran to the corner and started crying. I just can't believe that I would fall back so far to attack someone physically. He says that he has already forgotten about and he forgives me. But I can't forgive myself. I hate myself so much for giving in to the rage. I almost checked myself into the hospital. I don't know if I can ever forgive myself for doing this. Thanks for letting me post.