Will Botox Ever Cause Deformities or Permanent Bruising or Muscle Destruction if Used on a Long-long-term?

I just had botox done a few weeks ago and im only 21 years old , I do them for assymetry but im wondering if used for 20-30 years maybe , and everytime it wears off Will it ever cause my a deformity or muscle destruction or even Permanent bruising? I've read so many horrifying stories but there have been some excuses like bad injector or things like that , although i'm really scared of anything like that happening to me , i've already lived in alot of pain Please advise , thank you so much!