Congratulations on 90 days, that is fantastic! The first serious attempt I made at sobriety I started drinking again shortly after 90 days, and it was because I convinced myself I missed drinking activities, and all the fun that came with them. It led to three years struggling between periods of sobriety, and periods of failed attempts at moderation. On NYE of 2015 I decided to stop the insanity, and embraced sobriety. I have 20 months sober, and I wouldn't trade it for anything.
I promise you are not missing anything, stick with your sobriety, add something to your plan. You will wake up tomorrow and be so glad to be clear headed on day 91.