The last time my boat was wet other than rain was Oct 2016. I work a lot and have kids in activites that keep me busy but realize that will not last forever and I will have time to spend sailing in the future. I tried 3 or 4 times this last year to go but something always happened. Got home early from work hooked up the trailer then a thunderstorm rolled in, drove out to the lake another time to teach my son and the water looked like glass. I live in Texas and the weather can change in a heart beat so it happens. Sunfish are inexpensive to keep,maintain etc.. and I know I will regret selling it. Years ago I had a windsurfer that I sold and now I wish I still had it. Keep it till next summer and see how you feel then, you may drive by the lake and think about giving the sunfish another try.
What you state is the main reason I have kept my Lasers all these years ago. I sail only a fraction of what I did 20 years ago, but I still daydream about sailing. I still need to get out on the water every now and then. It costs me nothing to keep my Laser in the garage, and I certainly could not retire on the money I could get selling it.