if this is a serious question and thought going on here, please stop right there and think this through.
It is so simple.
Deal with one relationship at a time and sort out your marriage first. Looking elsewhere is not going to solve your marriage issues, it will only make everything harder and more painful all round.
I am guessing you have children? If so, think it through from their perspective too. You are not talking about a casual schoolgirl relationship with no ties, no responsibilities here. Think of the fallout and the effect you will have on all involved.
Stop thinking just about yourself and your needs and start thinking a bit wider than yourself. Re-read your OP - look at how many "I" statements are in there - "I miss sex" "I don?t want to ..| "I?m not sure" "I do understand".... doesn?t that ring any alarm bells for you? If you read this OP again as if it were written by another person, what would you be thinking??
Bit harsh maybe, but if you were in the room with me right now, I would be wanting to give you a big hug and then a big "wake up" shake! You know you are gonna have to talk to your DH about all this and how serious it is don?t you?