“Felling very stressed?”

You should speak to your school counselor and/or primary care provider about resources in your community. There are many ways online for reducing stress and anxiety, such as Calm App. exercise is a great outlet. Limiting screen time (gaming and social media) may be of help. Spend time with people you like and trust.
There are psychiatrist and therapists who specialize in treating teenagers and your adults.
Avoid alcohol, nicotine products and cannabis products and other drugs -- they only provide temporary relief but often lead to worsening of problems.

Because You are only 15years old, I highly recommend you visit your Medical Pediatric first, with one of your parents, and after that visit ask your doctor, if You can have an individual consult with him alone. He or she will listen to your needs.Don't feel sorry about asking for help. During our adolescence, we have a lot of questions that should be shared with our pediatricians. He or she will be glad to answer every question you have and referred you to a mental health professional if you need it. Feel free to ask for help. You are not alone.

Please go ahead and ask?

Consider...
https://www.noom.com/programs/mood/hm-paid?upv=3&sp=google&utm_source=g&utm_medium=paidsearch&utm_campaign=14185868854&utm_content=537771781590&utm_term=kwd-18365326|stress%20management%20in%20the%20workplace&gid=124844324879|&type=unbranded|b&cid=Cj0KCQiAweaNBhDEARIsAJ5hwbcDhegP1t8RP_yU3v9-2qywmUZQUQw3s2Kj59XYMozgmN1kqf2lbCwaAnOhEALw_wcB&pos=&step=pros&lang=en&device=c&product=hm&gclid=Cj0KCQiAweaNBhDEARIsAJ5hwbcDhegP1t8RP_yU3v9-2qywmUZQUQw3s2Kj59XYMozgmN1kqf2lbCwaAnOhEALw_wcB#/
and
https://www.nimh.nih.gov/health/publications/so-stressed-out-fact-sheet