I do exactly the same thing as you do Orl! I isolate myself mostly though because I find I get angry too easily when I am in that mood, and sometimes I will lash out at the people I really care about over sometimes nothing, and afterwards, I am very ashamed of myself. When I finally get to the point that I can cry, then I feel somewhat better. I think that a lot of my bad mood is because of anger, frustration, & unhappiness caused from not being able to change the way I am.
I cleaned my parent's deck for them not too long ago and unfortunately I was in one of those moods and my Mom came out on the deck numerous times and asked me where this or that was and it came across to me that she was thinking I was hiding the stuff in my car and planning on stealing it! I was hot, tired, and miserable & then she came out another time and told me that my sister called & was going to see a movie with my neice--- I SPAZZED! Flipped out... and my poor Mom slithered quietly back inside the house, not knowing exactly what just took place. I was so ashamed of myself after it happened... but at the time all I could think of was that my Mom thinks I'm a thief instead of being grateful for helping out and then my sister is sitting in some air conditioned movie theater grubbing pop corn when she COULD be helping me out with the deck. I thought of what it would be like to have a video of what just happened and if I would even recognise myself on it.... I think I would be highly disgusted and wonder why I'm not in an institution. Gosh, putting things into perspective, my Mom was just concerned she wouldn't be able to find her things, and it wasn't my sister's idea to clean the deck, why shouldn't she enjoy a movie! I HATE ME (even worse) when I get like that!
I have a very special friend that I have been corresponding with for over 2 years now, and I have explained these moods to him and explained to him that when I am in them, it's not a good idea for me to write. He understands, but unfortunately he found out about the mood the hard way! I lashed out at him over something ridiculous and I am very lucky that he is an understanding & sincere person and continues on to be one of my best, if not my best freind!
There have been people that attempted breaking the mood and much to my surprise, actually succeeded, because at the time, it seems like there is nothing short of killing someone or destrying something (and regretting it later!) that would get me out of that state, but likewise, some have tried and only made it worse and I've wanted to strangle them--- literally!
Anyway... if I could just reach that crying point earlier somehow, I know it would help, but I just can't seem to get there without some final incident triggering it.