Thanks for that thoughtful replies dingedheart and opalescent. I've been away a few days hence the late response. You are right of course there are many things inside that could do with a good hard look and a sympathetic self hug. Your posts made me think again about alienation.
I was with friends and acquaintances and some people I did not know this weekend and kind of watching myself seeing where I fit in who I like and who likes me. And my conclusion is that people generally like me and want to be friends. I'm not alienated in that sense I have a fairly good self image and confidence. I'm sociable and have a good time with my mates and new faces equally. The alienation is the regret with which I see myself sometimes do desperate things as a substitute for good old fashioned nooky. I'm disgusted with myself for that and it makes me feel lonely.
At this event there was lots of opportunity for socializing between sessions. A was there too and we had a great time chatting and laughing together and separately with lots of people. At one point someone brought chocolate brownies and I gave her hug. I could feel how I do that sort of thing spontaneously and I know its good and right because of her relaxed response. That's who I am I'm affectionate and people are OK with that and I'm OK with that. Then I looked at her and thought how nice it would be to have sex. It's not as if I'm in love with her it's just that I find women attractive. If you're lesbian opalescent you'd probably agree.
I guess what I was trying to say in my original post is the need for simple friendly affectionate sex with a wider network now feels like a basic unmet need like someone in solitary confinement craves company of any sort. The alienation comes from the stupid but understandable things I've done in unsuccessful attempts to ease the pain and especially from not having anyone to confide in. Of course the most important person in my life I should be talking to is A but as I've said it's not easy with her insistence on monogamy which I have to respect.
As for depression I think it's nothing more than suppressed frustration. I have lots of good things going on in my life and I don't dwell on negatives. But there's this hunger that I didn't understand until I read Sex at Dawn. It's so damn simple. I'm a human male and my engine runs on testosterone. I'll go look at the Restless Heart Syndrome thread now.
I'm not disagreeing with anything either of you've said about exploring the basic drivers. I'm just worried that I made myself sound a bit more crazy than I really am in trying to communicate my feelings. Not always easy for a bloke.