Lost and confused

I've been married for 8 years not and been with my wife for 10 years. Recently we've had lots of problems ranging from the loss of our income to me having cancer, moving back in with my parents her health deteriorating and us losing our health insurance. We did have a trial separation about a year ago but we both stayed in the same house which in retrospect I guess was a mistake we were both free to see other people but neither of us did. We made it through that but now things are getting bad again and I've been thinking about leaving her and/or cheating on her, which is not something I'm proud of or something I'd do litely, but I feel that I'm entitled to be happy also. My big problem is that above all else I think of my wife as my best friend we have loads in common and she is actually of the same intelect as me whivh is a blessing because I've dated some stupid people before. But if we split romatically I'd be alright but I do enjoy the talks and the fun that we have she is more like a friend to me then a wife and I'm afraid that it would end and I'd lose my best friend. We've discussed most of this but everytime we try to fix it I get the impression that she doesn't want to change. She hides on her computer and ignores me for hours on end talks to people and exchanges pictures and video chats with people that I don't know. We have a pretty open relationship as far as sex goes we have had threesomes that worked out fine and we both have a rule that if we really want to sleep with someone else that we just tell each other and we are free to do this I've never excercised this right that we have, and one time she asked me if it would be alright and I told her to go ahead but the other guy got cold feet and nothing came of it. But when I hint to the fact that I'd like to be with another woman she gets upset. I have a few other women that I'm close friends with and one of them specifically I have strong feelings for and until recently she has been in a relationship so I've made no move towards her or let on that I liked her at all though my wife knew I had feelings for her, the stuff you say to people when you're drunk, and yesterday for the first time in my married life I made a pass at her she turned me down but she told me it was because I'm married so I guess I understand her reasoning. My question is what would you do in my situation there is a lot more going on here then I've written so feel free to ask me to fill in any voids if you need to answer the question.