Concern over my conduct at work - Feel completely Helpless

My manager has called me in to discuss concerns over my conduct at work. I am a support worker for people with mental and physical disabilities.

I get stressed, I get upset - I try my best to not to let the behaviours get to me. The last couple of weeks have been extra hard due to various changes at work. I have ZERO idea what I have done wrong, because my manager won't tell me until I meet her, and it is stressing me out. The only thing I can think of is that a friend thought it was funny to send a link to me that I foolishly opened, which contained adult explicit material, and a female colleague was standing behind me.

Otherwise I have no clue what I could have done.

I don't want to lose my job. I try my hardest to get things done, to keep the residents happy. And I am freaking out, letting toxic thoughts into my head again, and I am very scared. If anyone could help, please do.