In my opinion, you're pretty normal. I became a widow a couple of years ago, my grown-up kids and grandbabies all live in town (but not with me - perfect world!) and I'm living alone for the first time in my 59 years.
I have to say I am really enjoying it. I wouldn't have chosen this, but since this is what life has handed me, I've found that I like being alone. I work during the day and get along well with the folks at work. But when I come home, it's peace and quiet and whatever I want to do.
I've often told myself that I need to get involved in church, or join a quilting guild, or something like that. But I've finally come to realize that I enjoy my own company and don't want to change that right now. I figure that when I retire I'll get the ambition to get more involved in community, but we'll see what happens when that time gets here.
I think people who tell you that you need to get out more may be people who are more extroverted - they get their energy from being around others. I am introverted - I get my energy from alone time. And there's nothing wrong with that as long as I am happy.