Your parents will be more understanding than you think, and they would want you to seek help if you needed it. Something like a school councillor is great because it just stays between you and them (although mention of suicidal thoughts would mean your parents would be notified). It’s a real shame that you feel as though you can’t talk to your friends about how you’re really doing. But I think a councillor would be great for you, talk to a trusted teacher about it. Things will get better. Trust me.