Lost a friend because her new boyfriend has gaslight her into thinking all men are dangerous and want her sexually

I’m a man, and recently I’ve had a falling out with my friend, and I’ve found out from some of her female friends that she has cut ties with all man in her life apart from her bf of 3 months and close family.

She is only a friend to me, and I valued her as a friend. She asked me to study with her for our tests and I agreed because I want to do well. It was nice sitting with someone while reading though textbooks. I found that really productive, and the short chats in our breaks was a good way to know people.

She called me her best male friend, I also invited her to some of my social events (like playing monopoly with friends, I don’t drink)

I knew something was up when I asked if her boyfriend would be interested in going. She later told me that her boyfriend thinks I’m “Really ugly” and he’s “not interested in meeting me”

While summer break was on, i had a Job in the United States, so we talked and I shared what was going on, and she went back to Romania for a week, and I asked her about that.

She unfollowed me on instagram, I soon found out, and asked her way. She raged at me about how strange and weird it was to study with someone you know has a boyfriend. I just left her on read. Because idk what to even say about that.

I asked a mutual friend, and she said that her boyfriend has been slowly filling her head with all men are dangerous stuff, and he clearly had something against me. She also said that when she was around he would sometimes talk about me, and who he thought I was “just trying to get with her” He has never met me in person.

He has more or less full control over who she socialises with, he’s clearly insecure so didn’t want any other men in her life.

Idk what to do? I’m insulted but I also can’t blame her if she is being manipulated. How can I avoid another hurtful situation like this one?