Looking back on times when my mental health was at its worst, all I can think of as an answer to this is 'yes'. But in reality, it's a no. I wasn't a monster, I was unwell, and I've been totally suckered into the idea that having a mental health problem means that I'm not a 'normal' human being. I'm deformed in some way. I wasn't some kind of terrifying beast that rampaged through towns, pillaging women. I was however both a 'frightening creature' to myself and someone that was horrifically cruel. Both of which count as definitions of what a monster is.
I'd lost who I was. The 'new' mentally ill me was someone who I didn't really know anymore. Mental illness makes you question every single thing about yourself. It sucks you in to an illusion of what it wants you to think. Suddenly you're not quirky, you're an absolute freak that no one wants to befriend, and you're not curvy, you're disgustingly overweight. I became so consumed by these thoughts that I completely believed them. I was so convinced that I was utterly unloveable because of a myriad of destructive self-hating thoughts that I turned this misery outwards.
And this draws me on to the second definition. As well as becoming a frightening creature to myself, I began to be devastatingly cruel. I was so wrapped up in a world of despair that I didn't care what I did to other people, or how it might impact them. I wanted to be alone in my depression, and as such, I pushed everyone away as much as I could with vindictive words and behaviours designed to make them hate me. Sadly, for the most part it worked. Luckily for me, a few people who were close to me saw through the cruelty to see someone who was simply hurting.
What I'm trying to say here is that my mental illness turned me into someone I didn't know anymore, and didn't particularly like. It made me feel like a monster, but I wasn't really any different from anyone else. There's no need to dehumanise ourselves or others struggling with MH issues with terms like 'monster' or 'psycho' or anything of the sort. It's degrading, unnecessary and no matter how awful your mental illness makes you feel, you will never be less of a person because of it.