Hi there
It sounds like you are struggling to cope with some really difficult feelings. I'm wondering what makes you feel so sad when you say you do have friends...that seems to show that people do like you, what do you think? You mentioned that you don't want to put your mum through the stress you had with your last school - it might be useful for you to talk more about what happened there?
Sometimes people going through a tough time go into 'survivor mode'. This means you try to deal with things as they come and you don't really get the chance to feel what you need to feel because you are so busy just trying to get through. Then, when things calm down a bit and you feel safer, those feelings just spill out, whenever they can. Does that sound like it might be true for you? Feelings can be funny that way, they always seem to find a way out.
I know you say you don't want to talk to anyone and feeling like that does make a lot of sense, however, sometimes just having a listening ear and a safe place to express yourself can help you overcome the difficulties you have had to survive in the past. Talking can be a very useful way of getting your feelings out without trying to hide what you are going through. You don't need to hide, what you feel is real and important.
If you want you coult talk to a counsellor here at ChildLine about this - they are here to listen and support you. You can contact a ChildLine counsellor on the phone on 0800 1111 or you can come talk 1-2-1 advice using the online chat.
Take care and remember, we all sometimes need a helping hand. You are not alone.
Sam