Hey there,
Good on you for quitting! I've smoked for about 6yrs with most of that time smoking alot everyday. A couple of years ago i stopped for 6months and honestly felt great like my life was mine again. Stupidly i had just one bloody toke and stared smoking everyday again for a guess about 6months to a year. Newyears eve at midnight 2013/14 i stopped and havent touched to stuff at all since. Im 90 days today (woohoo).
So basically its definately worth stopping if you want to. I stayed away from my pot smoking mates for the first month or so because i was really craving it. Now though i hang out with them while they smoke and it doesnt bother me at all. So dont think you have to permanenltly ditch them like i thought originally, and used as a reason not to quit. You'l still see them, although probably wont like them as much when you realise they dont ever want to do anything besides smoke haha.

Ways i feel better:

1) clear head, i know me, my moods and motivations. I dont have weed muddying the waters confusing me about what i want and think.

2) embracing life, i want to go off into the world and see things meet people not just stay sitting in the same old places getting high.

3) im saving no end of cash!

4) no more meeting dodgy people to buy weed, feeling paranoid and to be honest at times putting my self at risk.

5) my dog likes me more now i stink a bit less.

6) i dont miss out on family gatherigs because im to embarassed about being off my head.

7) despite common belief i actually have much greater intuision and insight now iv stop smokig.

8) my day isnt ruled by how much weed i have, when i can get some or will i run out, putting me in a bad mood.

9) honestly i feel proud of myself for quitting and its giving me the beleif in myself to do other things i wouldnt have.

10) generally im much happier, much more stable and way way more optimistic and positive thinking.

I could have put more things but i didnt really want to ramble too much, but yea there you go. Hope someone finds this useful.