Hi and welcome to PC👋👋
I think all your thoughts and concerns are legit. You have things you feel you want to discuss with someone who will be accepting, non judgmental, helpful, and a therapist is a good approach to take in that respect.Their whole mission is to help. I don't think it's a waste of anyone's time at all, and being a 17 year old is a time when some good guidance is a welcome thing.
I'd just like to say I think you're taking a wise approach towards your life. Keep it up. 🙂👍