I understand you needing to find your new normal. I have given this very topic a lot of thought. Cancer has certainly changed my life and how I live. I decided to pursue two things when my treatments are over: fitness and learning Spanish. I really thought about things I would enjoy and want to do and that's what it came down to. I have started to plan by finding a local club that speaks Spanish and looking at the activities a local outdoors organization hosts. Looking at the upcoming events makes me look forward to being done with treatment and moving on with my life.
Networking in a room is the #3 fear of people. You are not alone in having trouble connecting with people. May I suggest taking a class at your local community college. They often offer community classes like gardening and exercise and languages. Meeting someone in a class is easier because everyone is in the same boat: they don't know anyone in the class. Working on projects together and sharing ideas is a great way to foster new friendships. Some of my closest friends, I have met in classes I have taken.
Good luck to you and congratulations on finishing your main treatment. Give yourself a break. Making friends is hard work but the hard work can pay off.