Ouch I have lost myself again
Lost myself and I am nowhere to be found,
Yeah I think that I might break
I've lost myself again and I feel unsafe
This part is saying that she was clean from self-harm for a while, but she's done it again and she doesn't know what to do. When she says "I feel unsafe", she is saying that she is afraid that she might commit suicide. When she says "I think that I might break", she's saying that she things se might get deeper and deeper into the oblivion that is depression and she might do something irreversible.