I second Lady Gene’s suggestion on working on self-acceptance and self-love.
Negative energy goes both ways when it hits us emotionally. There’s the element of those sending the energy - but also on the other side it’s our willingness to accept it. What you went through clearly was traumatic and that tends to distort the mind when it manifests as survivor’s guilt. If there’s a part of you that believes the accusations, you will absorb their negativity more readily.
And most importantly, that event is in the past - so working on releasing that attachment to that memory will help release you too. You could try cord-cutting with these ex-friends. You could try working on your grounding and protection, like Lady Gene said. Chanting mantras for self-healing can be highly effective - I have ones I can suggest inspired from my own practice too.
If you want to know a good entirely flame-free, tool-free self-protection ritual, I will direct you here:
Let us know if you need any clarification or further suggestions. 