Sometimes, when you're very unhappy, you might want to stay at home to avoid the bullies because you're afraid of what they might do to you.
Always tell your parents how upset you are so that they can help you. You need their support. Every day you go in to school is a triumph over the bullies because you're showing them that you have every right to be there and that their behaviour hasn't upset you as they'd hoped.
Staying off school can make things more difficult the problem is that if you start taking days off then you can quickly fall behind with work and that makes life more stressful as well as possibly affecting your exam results and your future.
Unfortunately, taking time off school without being genuinely ill is considered to be an unauthorised absence or truancy and your parents could end up being prosecuted for it.
Luckily, council education departments have people who can help in this situation called education welfare officers or education social workers and they can often make a big difference so that pupils can get back into school quickly and with the support they need.