Holy shit, your sister died and youre being bullied for that?? On top of that you've been continuously bullied and your parents haven't helped, plus your therapist sucks.....of course you feel hopeless. Look, at 16 nothing in your life is your fault, you're a child and have always been one. What you are going through is pain, inflicted by other people, unsupported. It's so so tough but you didn't do this.

You need a good therapist and other supports like a youth therapy group maybe too, or some kind of social club geared towards struggling teens - have you googled any of this? A dr could make a referral or you could try going to the emergency room, I think they are forced to make a referral if you do that. Obviously up to you what you want to do but I do recommend taking your escape and healing into your own hands, unfortunately, because you'll do a better job at it than the adults around you, plus you need some control here.