Maybe the life situations that have caused your depression have also caused the nightmares rather than the medication, especially since you have been doing so well with it. Before jumping to any change with your meds, maybe talking out the life events with someone would be helpful ... and make your nights more peaceful. Talking things out with an understanding person always helps me.

BTW, I also had vivid nightmares last night but I have had some major life changes/challenges recently and I ate a big dinner very late.