What you mention about Wilson, that being "alone" means "not being in a relationship" is my least favorite thing about him, and I think is his biggest fault. And, like you say later, it causes him to fail to recognize how important he means to House as a friend, how not alone he helps House feel when he's around as his friend, not his matchmaker.

I totally agree, and I kinda love him for it in a 'Wilson, you darling twisted moron' kind of way. I also agree about the side-effects of Wilson's matchmaking, although I secretly suspect House would be disappointed if Wilson drew back too much, because that translates into Wilson no longer cares in his warped brain. They really have no sense of boundaries, and in House's head, irritating and intrusive matchmaking quite possibly translates into an expression of love.

But more than being pushed away through the matchmaking, what has made House feel even more alone is the return of Daniel Wilson. It's a neat parallel to Cuddy and Rachel, the fact that both of them now have new families, and that evidently means they no longer love him anymore. I'm not surprised that the therapy visit has followed 'The Social Contract'. I also wonder if he is very well, physically... (Um, haven't been following spoilers lately, don't tell me.)

House's fear and loneliness and pain is driving him to act

I agree. I'm not certain how much 'romance' really comes into the scenario - this show doesn't really do straightforward romances anyway. It's consistent with what he said on the bus - not being miserable translates into reaching out to Wilson and Cuddy.