I really need to learn to be less reserved, more spontaneous and have fun more - have high energy

IT's been going on really long time now and is making me really unhappy because I feel like it never gonna change

It's the old story of 'around people I know REALLY well I'm fun and mess around' - I dont know how to be that though with 'normal people' and people I don't know

Everyone else is laughing, and back-slapping and high-fiving around me with each other and I just seem socially awkward and quiet

I used to have energy more naturally when I was a kid, but for last 15 years it's been mostly gone (aside from occasional moments on drugs / very drunk etc - so I know I 'can' do it - just don't know how to get it naturally).

Here is the best advice I can give you as a divorced guy who is a single parent who has been in your exact shoes. I used to ask myself that question every time I went out! This sounds lame in a way but it struck a cord with me. I was watching the fast and the furious Tokyo drift and there is a scene in the movie where the guy who is Han says " life is easy you make decisions and you don't look back". YouTube it and check it out for yourself. Basically I started living my life that way and you know what? I've never been happier, let that inner you out. Fuck people let them think whatever they want about you or me. I cannot change how people view me or you, so I stopped caring which explains why I thought singing ain't nothin but a g thang at karaoke was a really good idea. Is it really easy to just say fuck it? No it's not but you have to keep
Trying, whenever I feel that reserved me tryin to come out i think back to that quote and do whatever it was that made me question myself.