Hi hahalebou. I'm really sorry you're feeling so bad. It probably only feels worse, coming on the heels of feeling so good, right?
I hope your good mood was just that, and an indication of positive changes you are making. Sometimes though, feeling of intensive happiness, increased energy, feelings of being "unstoppable," or "invincible" can be symptoms of a manic episode. Do you have any history of this? NOT trying to diagnose you, just giving you something to consider.
Was there anything you can recall that helped spark the good feelings you were having? If you can think of any circumstances that helped you feel better before, sometimes you can recreate them to help yourself feel better again.
I hope today was just a stumbling block on your way to happier times. Just because you felt bad today, doesn't mean you'll feel bad again tomorrow.
I hope you'll wake up tomorrow feeling good again too. Thank you for sharing this!