Confused about my sexuality. Am I bi or lesbian or mostly straight? What should I do?

So I'm 26 and I seem to be attracted to both sexes, but it is weird. A lot of times I get so nervous around women. Women are more physically attractive, but I can't picture myself ever being in a relationship with one, I didn't used to get sexually attracted to them before I was 22 or something, so it all felt really weird. I've never messed around with a female, but I've posted ads in the personals. My old friend switched her sexuality from straight to lesbian to bisexual all within a month. Her body language at first made me think she was sexually into me, but when it all came down to it and she probably knew, I didn't ask her because she didn't seem interested. Sometimes when I'm around women, I get clumsy or nervous or I'll salivate more and my words won't come out right. Men relax me and make me feel comfortable (if we're not fighting. And even then, I'd rather have an argument with a guy.), and I feel like I can be more myself and they won't judge me, and I like that. I don't really want to do anything sexual other than kiss because I feel like I am touching myself, and I don't like to do that. I've done stuff with a lot of guys but only had sex with one,and I lost it when I was 24 because I wanted to save it, but he needed it, and I loved him too much to let him go. He was bad in bed and didn't give me foreplay. I enjoyed it when he gave me 10 minutes of it or used toys. I am just so insecure about liking women. I love my ex-boyfriend. I don't know what I should do. I don't want to be gay. I don't think I am, but I don't want to be mostly gay or right in the middle either. If I did want an experience with a female, I wouldn't know what to do or where to go finding someone to experiment with. I never got responses to my ads that I felt comfortable with. If I'm not gay or mostly gay, I want to know what I can do to overcome my nervousness around women. Being insecure sucks.