Its sounds as if things are of concern, especially having thoughts of suicide but only a psychiatrist could provide a diagnosis. Depression is very treatable though. I would speak to the school guidance counselor and see if they can talk this through and suggest where to go from there unless the tetacher has some direct referrals.
Please do not brush off your symptoms as "hormonal" or something to do with being a teenager! I have come to realize that I have suffered from anxiety & depression since a young age and wish I had sought help much sooner than I did. Don't wait until you hit rock bottom to ask questions about what you are experiencing. Talk to a school counselor, your doctor, a trusted family member, anyone, but please don't ignore your concerns. You know yourself better than anyone and if it concerns you, you should look into it. You should be proud of yourself for recognizing these changes in yourself and looking for help!