The real world doesnt revolve around drugs, real sober life has alot more genuine things to offer(Genuine in the fact they wont cost you your health/Sanity/IQ). The pessimism comes from not knowing anything else/better outside of that lifestyle. I remember feeling completely redundant and also pretty 'Braindead' from my lifestyle. The 'Health' Hobbies are always good, wise and empowering. Take this time to focus on yourself and build yourself up; Diet, Exercise, Sports(low/high level, Solitary/Competitive). Keep an open mind and whet your appetite for an Interest that Grabs your attention and also 'Improves' you in some way(Socially; Meetings?, Intellectually; Reading, School, etc , Spiritually; Music, Nature, Volunteer groups etc). The more you are looking after yourself, the more confidence and trust you'll gain in yourself, and therefore , you will be able to allow yourself to enjoy things rather than constantly seeking for something else to depend on for your happiness.
Do make concious efforts to reward yourself everytime you try something new, no-matter how small-dont ever take yourself forgranted!
I know it can be really difficult to Adjust to a different lifestyle but once you let go and Accept the reality that there are better things out there for you, than being stuck in the rut of a Substance based lifestyle, you can start to see that you will eventually have more Freedom and Scope to choose whatever works best for you, being Sober. Keep Strong, Sometimes your only starting to get to find out who you really are and what works for you, although it can be tough, look at it as a 'Rite of Passage' for yourself. Remember ,to take it easy on yourself dont beat yourself up if things dont run as smoothly or as fast as you'd wish-sometimes its experiencing how you get there, and not just getting there that matters!