Can't look forward to getting high

First I'd like to give you props for quitting smoking pot since you've expressed how it has made you feel terrible. You didn't mention if you have support set up to deal with being sober or just having quit on your own.  What you are going through is very common.  After 12 years of smoking pot, you are very used to using pot as a reward and likely a way of relaxing.  You're hardwired to anticipate and reach for pot after doing something hard or difficult.  Without being able to satisfy the desire, life may seem empty and, indeed, like there is nothing to look forward to.  This is part of the addiction. How have you used pot to self-medicate as a way of dealing with problems or boredom or uncomfortable feelings?  Learning to find healthy ways to reward and relax is not easy after 12 years of using pot to do so.  I would recommend finding a group (NA - Narcotics Anonymous) where you can get support from other people going through the same struggles with drugs as you are.  Since you didn't say how much, often, why and if smoking pot affects your life (motivation, relationships) in negative ways - aside from feeling terrible when you smoke - I don't know what would be most helpful .  But finding support and commonalities with others can help you address the difficult issues of giving up getting high.