It is not normal for You to question "suicide" and it is not normal for all teenagers to feel depressed Hun, You seem like You are going through a really hard time and it might be best if You find someone to speak to about this in person; a school counselor, a local therapist or trusted adult.
You do not have to go through this alone there is always someone wanting to listen and someone who cares, You just need to reach out and let people know You are need of it.
It is really good that You took the time to post on this forum and reach out.
ProudMumToBe is absolutely right that it's not "just growing up" to think of harming yourself. And even if it were, that doesn't change how you feel. Don't let anyone make you think that you're weak or a bad person or "silly" or whatever because you're having trouble coping. Being young doesn't mean your feelings are less real than anyone else's. I had a major depressive episode starting when I was 14 and my parents thought I was just "being emo". They realised their mistake later on and now my mother says she feels terrible that she dismissed my feelings as youthful nonsense.
This is probably mild depression (but just because it's mild, doesn't mean it's to be ignored or that it doesn't matter - mild depression can become severe depression). It is a completely understandable response to your situation. I would recommend seeing a counsellor or psychologist or some kind of therapist, who knows cognitive-behavioural therapy (CBT). That's important, because it's very effective in dealing with problems - everyday problems, depression, anxiety, sleep problems, eating problems, everything. It can help you out and just as importantly, keep you happy when you're through this and feeling happy again (which WILL happen, I can just about guarantee).
Just ask whichever therapist whether they know CBT (they almost certainly will, it's quite common) and try them out. There are bad therapists out there and good ones, so if you get one that doesn't help, don't be afraid to ditch them and find another. It's vital that you find someone that connects with you properly. And it's not your fault if that doesn't happen.
Anti-depressants are over-prescribed in America. Whatever you do, don't let some doctor just give you anti-depressants and not refer you to anyone who can give you "talking therapy". And don't even take anti-depressants unless you really believe that you can't get through without them. There is nothing shameful about taking anti-depressants and in lots and lots of cases they are absolutely necessary for becoming well. But nevertheless you don't want to go on them unless you have to - they take weeks to kick in, there are some side effects, there are withdrawal symptoms when going off them, adjusting symptoms when going on them - not terrible things, but things you don't want to deal with unless you have to.
Also, try talking to your closer friends about it. They may be surprised and a little overwhelmed at first, but you'd be surprised what little things they can do to help - staying up late one night comforting you, doing something fun with you to take your mind off things, encouraging you, telling you they care - simple things like that. Your therapist will be able to tell you - and maybe them, if you're okay with that - more about that.
I'd say try the school counsellor first and if they're not good, see whom your GP refers you to.
Good luck! I was severely depressed in high school - I couldn't function at all, not at all. But look at me now - all A grades at the best university in my country (admittedly it's little New Zealand), a great boyfriend (after many terrible experiences with men), job offers. Think of this as the horrible chapter in the novel that passes and then comes the happy ending.
I used to feel like you, from when i was 12-21. its getting better slowly but i didnt get help for years because i thought no one could help me. please go and see your doctor, tell them exactly what you have wrote here. They should refer you for counseling and you might have to see a psychiatrist but they will be able to stop you from feeling like this. good luck xx