The old saying opposites attract is so true. My xh and I were exact opposites. He was the introvert and I was the extrovert, i.e., different as night and day. Extreme? Possibly. It worked well until he hit 40 and then things began to change due to the crisis. He never suggested doing anything, so...I was left w/the planning and yes, he would participate at times. I would not try to control and/or make him feel guilty if he didn't participate. We use to have some tradeoffs like he would do some things w/me and I would sit and read and/or watch TV w/him.
Your situation sounds a bit like mine was. You either have to accept them for who they are or move on w/your life. You can't change them. If you haven't figured it out yet, if you want this relationship to work, you'll need to go out and do the things that you love and if he doesn't want to participate, then leave him at home doing his own thing.
As for friends, my friends were his and the same applied to his relationship w/the ow (deceased wife)i.e, her friends were his. Now that she's passed on, I have been told that he doesn't associate w/them any longer and is pretty much a loner. The only time that he could make friends or initiate conversations w/strangers was if he had a bottle or glass of beer in his hand. I guess the alcohol gave him the courage to reach out of his comfort zone to "loosen up" and chatter. He had difficulty maintaining conversations and relationships w/people.
The crisis is definitely a chance to re-evaluate both of your lives. The bigger question is this...are you willing to be patient and allow him to heal and figure things out? The changes that you make, must be for you, i.e., not to win him back. You have to be happy w/those changes and they must become permanent.
Sit quietly, the answers will reveal themselves when you least expect them to. The past is gone, the present is a gift and you need to focus on today, allow the future to reveal itself when it is ready.
