Hi there
It would seem as though your family are placing a lot of pressure on you to do well in your exams. Shouting at you to get out of the house is really not very helpful either.
Parents do want their children to do well but sometimes their encouragement just creates more stress.
They can often forget that exams and outcomes are very different from when they took them.
It maybe worth trying to choose a moment and talk to them. Be honest and let them know that what they are saying to you isn't helping.
You are studying as hard as you can and can do no more. Everyone has different learning abilities, for some it comes easy others find it more difficult.
Take a look at the ChildLine Explore section for tips in dealing with exam stress and have a look at the ChildLine message boards too.
You say you are also having problems with accessing online chat. Check the Ask Sam topic about ChildLine chat.
This will give you some help on how to check your own computor and how this should solve getting into 1-2-1.
I hope this helps and good luck
Sam