I can't believe this!!! Please what do I do?

I just found out my husband is CHEATING!!! That's not the worst of it...he's cheating with my sister! She told me last night after I found a letter he was hiding in his truck. I had to keep myself from kicking her because my 5 year old was standing there and he just adores her?! What am I going to do? My husband is away on business til tomorrow and I know that tramp called him and told him I know! I don't think his guilty behind will even come home. Hey can I get arrested for piling his belongings on the front lawn and setting them on fire? I can't believe this!!