How do I get back into this particular spirit?

I used to gather a bunch of friends for hang outs or you know, for special ceremonies over the years however, as cliques formed more and more and friends leaned towards networking with people in the same fields, or social functions I got turned off as only certain people would appear. I know it’s part of growing up, but I at least want to get into the festive spirits and invite my friends for birthdays at the least, you know, things of that sort. Should I also try to hang out with these people when I have time? Instead of enjoying my down time alone? Should I also go to every invitation for a function or social party? I admit I have been taking a step back in following through with being invited. As in, I’m the type to be like, “Yeah I’ll let you know!” Instead of being definite of knowing whether I’m going or not. The truth is I’m most certain it’s about 55% I’m not going when I put up an excuse and 45% that I will go. And then when I do go, I get the feeling of, damn I shouldn’t have gone (that mostly happens when I end up getting a ride and have no control of getting back home on my own time since I didn’t drive myself.)

Are there any other young adults who struggle with these kind of situations? I’m 24, I miss my friends, but I also know what I like. I’m just trying to make an effort to invite old school friends to birthday functions, and stuff like my childs birthday, things like that.