Well I think you are doing the first thing right and that is to do something about your drinking, as that will hold you back whatever you do.
I've lost jobs, places I've stayed, girlfriends, friends, valuable possessions, self respect and anything else you can think of through drink and latterly I feared for my health too which is what I probably needed to get me to seriously try stopping.
I'm doing tons of new stuff that I didn't do before - eating healthy, exercise, reading, watching films (and actually knowing what is happening in them) and stuff.
My social life has taken a severe dent mainly because I've chosen to sever some ties that weren't healthy as they'd very likely lead me to drinking again.
As for being happy with my life just now, I guess I'm not yet - I make enough to pay the bills just like you I feel like I haven't realised my potential yet either.
I got kicked out of university in my early 20's (mainly due to drink, absence, lack of commitment, partying all the time) and have never really recovered from the shock of that happening (and I used to blame everybody but myself for that, I take full responsibility now) but now I'm doing an open learning degree (was fortunate enough to be able to transfer credit over from my previous study) which I'll be able to complete as early as next year and I can honestly say that things are looking up after nearly 6 months (6 months on the 19th of this month) off the drink.
I think you'll definitely see new opportunities for yourself when you find you are able to get up and make things happen which you probably couldn't do when you were drinking - drink holds you back, limits your potential - once you settle into your sober routine you'll begin to feel more positive about yourself and hopefully be clearer about what you want to do.
By the way, 38 isn't old these days and it's never too late to start doing something new - have you thought about what directions you'd like to go in? Look at the stuff you are good at and/or enjoy doing and maybe start from there.