Hello I've Been Taking Bilocor For 3years Now And After

Hello

I've been taking Bilocor for 3years now and after my first year of usage I have gained so much weight it's crazy. Is this one of the side effects?
Also, am I able to stop the Bilocor as i don't need to take it anymore.
Initially it was prescribed for anxiety ( my heart rate was too high).
I really wouldn't like to be using these ends forever.
Plse ,et me know
Thanks