Welcome to SR, very intense and honest post.
I'm a 40yo father of an 11yo and now a newborn. My addiction to the booze progressed along the same lines as yours has - eventually devolving into barely manageable day drinking while I tried to maintain a high stress professional job.
I'm sober now, after many many attempts and failures. Sober for good.
I can tell you that even 90± days after my last drunk, (longest I've ever been sober since I was a kid), that the worries and questions you have about happiness and anxiety all start to get solved, if not resolved. Sobriety turns out to be full of peace, calm and plenty opportunities to find happiness. Yes, life is still rife with frustration and sadness, but it's so much better is a life.
I can read in your post just how deeply you want to get sober. I used my kids as leverage to finally put down the drink for good. You can do the same. But you need a plan. Do you have a plan?