Is this Anxiety? Or me going CRAZY?

Hi, I am almost 19, and one year ago I had one, i repeat ONE, panic attack.. Since then i have been a different person.. I have taken Lexapro, and then moved on to these other pills. Since then I never experianced another panic attack, but what I am experiancing is, that i am trapped completly. I consider earth, this planet a big ball or bubble that is keeping me inside... and i wanna freak when i get thoughts of being "closed in" or "trapped"... but its weird because instead of that... i feel weird and get mood swings... and feel crappy one day, and happy other days... but the good thing is these pills are helping 100%.... but, i still feel weird ALOT.. so I do not know what is wrong with me? the doctor said im fine, thats the symptoms of Anxiety, and that these pills will slow my mind and not think.. but aye, damn.... it's reallly HARD. everything that affects me, i get different feelings.. ugh. Help?