Dude, welcome to the board!
I was a big time stoner for years, myself, although it was opioids that finally dragged me down.
I can tell you for sure that YES YOU WILL (for the most part) feel increasingly better after quitting weed, or any other drug for that matter. That stuff can keep you in a bit of a haze for a while after you stop it ... THC being fat-soluble and all that, as I'm sure you already know ... but yeah, give it some time, and get involved in some kinda recovery program, and you CAN do this thing you speak of. There ARE secular recovery groups as well(SMART, Lifering I believe are two of them) that people have success in, maybe check those out. And for my part, I'm an AA/NA goer, yet I'm still a hard-core agnostic bordering on atheist, and likely always will be, so ... go figure!
Good luck, and keep posting
One other thing ... this part:
I have been wanting to quit weed <snip> At the same time, I feel it has been one of my best friends and I am not sure how I am going to cope without it.
I s**t you not, EVERY SINGLE ONE of us addicts/alkies on this board that's clean today (and most likely, in the world) felt/believed EXACTLY the same thing when we were still struggling to quit, or just beginning the recovery process. This is very natural, as I say, we ALL go through this. And you know what? It is bullcrap, it is the DISEASE talking. You CAN LEARN to cope without dope my friend. And it'll turn out to not actually be THAT hard, not as hard as you imagine it will be. Recovery groups can teach you how. Go there. Listen. Learn...