2.
Build deeper connections with those around you
It sounds like you have a pretty strong social group but you just aren't really connecting with anyone on the level that you crave. There are plenty of people in your life but if you don't open up to them then how can you really get to know them and let them get to know you?
Yes, these things can take time, but in order to make real friends you need to be a real person. Don't try to pretend you are something or someone you aren't so that people will like you, just be yourself and you'll see that people will be drawn to you.
Yes, this is easier said than done, but start with someone you trust. If you are married then start with your spouse. Or start with one of your best friends. Just be open and honest and share a piece of yourself that you typically wouldn't. It could open up a whole new world of possiblies and a deeper level of connection that will make you feel like you are understood and ultimately not alone in the world.