Hope this is the right place to post this

Hi, i've been on and off Citalopram (20mg) since around 2008. for the first i'd say 4-5 years i stuck to taking it everyday. then the tiredness got to me and the thoughts of "maybe i'm ok now" come along and i started going throught patches of taking and then not taking it. Also for the last few years stuck to 10mg

last year i mostly went without taking it but had a really bad end to the year. This year started taking 10mg every day. still constant thinking every day but not hugely anxious or depressed, just the feeling down (feeling everything turns bad etc) once in awhile. then i decided to up to 20mg and my head just went crazy, i just couldn't control my thoughts, feeling panicky etc. thinking stupid things, being hugely melodramatic etc i stopped taking it altogether the next day i felt normal again. still with chatterbox but i didn't feel everything was turning to >>>>.

I confessed to the doctor who put me back on 10mg for a months and the up to 20mg. that started 12 weeks ago but just doesn't seem to be helping that much i've been panicky and depressed, the head chatter has been really bad anytime i try to enjoy watching films or tv.

Apologies for the long post. my question is could the stopping and starting have effected my brain permanently? could i just need a larger dose or could i need to try another SSRI?

Thanks for any help