So you dont want to be with him. You have settled. If so you will never be happy.
I agree with pp, that an open marriage may be the solution. But only you know if this would work with you and him. Some people have great open relationships. Some dont.
I suspect you wouldn't, because if you met someone, was sleeping with them and you both got feelings for eachother. You would be off like shot. That's not judging you. But this isn't a happy relationship, that you are only in because you dont want to be alone.
If you are unhappy in your marriage and sleeping with other people and theres a chance you can have a better relationship and life with someone else rather than your husband, you will want to leave your husband.
If marriage with no sex is not for you (and I don't blame you for this, Its wouldn't be for me either) then you probably need to end the marriage.
I think you know, deplep down you shouldn't have married him in the first place. You ignored the issues, probably thinking it would get better and because you didn't want to be alone.
Again, this isn't judgment. I can understand that. But if you arent happy qndbits not going to improve. You would be best moving on.