Bipolar or normal ?

I can’t figure out if I’m bipolar, or if I’m normal, or if its low serotonin, permanent mental damage, or what the problem is. I took Ritalin for 8 yrs when I was in lower school. I also took ecstasy once or twice a month for about 2 yrs (this was 5 yrs ago).
(Present time: 8 yrs later) Right now I only drink socially and I go to the gym and do not take any medication.
I am always feeling up’s and down’s. The roller costar is not as severe at this exact moment, but in the past 2 yrs I always felt tired no matter how much sleep I had. I always put myself down. I waste hours of my free time thinking, almost in a daze without even relising how much time passed. Anything triggers depression for me. A song may come on and all of a sudden I’m so sad and think about how stupid my decisions were or that I’m good for nothing. I always am trying to find a sense of identity. I have little confidence in myself to ever find a husband (and for that matter even b/f).If I’m drunk sometimes I will get flash backs from a very bad night I had on ecstasy (5yrs ago) I think about suicide sometimes. Then on a completely different side I can feel very happy, going through the everyday routine of life.
I can’t keep this entire drama going. I want to feel happy and confident all the time like my other friends. Did the Ritalin contribute or the ecstasy or is there mentally something naturally wrong?
Thank you for taking the time to read this.