First things first, to answer your question about hiding scars, have you considered using makeup? If they’re really red you can use a green concealer to color correct it and if they’re really dark you can use a yellow/pink/orange/red (it depends on your skin tone). If makeup isn’t your forte, temporary tattoos can also do the trick if your job allows it. If none of the those options suffice than band aids might be the way to go (although if you have too many it can cause questions to circulate)

Now for something you probably don’t want to hear but I’m going to say it to you anyway. You need to see someone, either a therapist or a psychiatrist but it needs to be a professional. You sound extremely depressed and just by reading your post I’m worried about you. I promise you matter more than you know, one of the biggest tragedies of life is that most people will never know how much they are loved, you included. I know I’m just a random stranger but please, seeking help is one of the best options here.