It's actually perfectly possible to cry hard one moment and then laugh harder than life the next, especially if you haven't been able to do either in a very long time. When the emotions do come out, they pour out. Too much pressure in the spill way, you know?
All of those, especially the dysthymia is perfectly possible and should be further explored. I know it's easy to just assume that everything is all just made up because it isn't physical. But it is real, very real and shouldn't be shoved aside. It's really a good thing that you let those emotions out, that's healthy and needs to happen. You also need a healthy support system there to help guide you through it, or at the very least just sit with you until you're through the episode. Your pain, your mental state, is very real and should be treated as such.