Cheating Husband.."had too much to drink...."

I've been married to my husband for five years. We have two girls. Last August when I was pregnant with our second child, my doctor told me I had an std.

When I asked my husband, he told me that at a work function, he was with a girl, had too much to drink, and she gave him oral sex...

once he realized what was going on he stopped it and left. I don't believe that that is all that happened, and to me, he crossed the line with her before anything sexual happened.

I have been suspicious of him before not being faithful but had never had any evidence. It has been seven months since I found out.

He has done a complete 180 in the way he treats me and lives his life. However, I feel like he is only this way right now because he is scared to lose me.

I know that I need to leave him and I think the reason I am still here is because of our girls and how I think that it is important to stay for them.

Has anyone left their spouse with children? Any advice?

Thanks