How do you tell if you have Gender dysphoria or are just confused?
Go to mixed trans meetings. Talk to a lot of different types of trans people because there's a lot of different ways of being trans.
Also, get a good therapist who has worked with trans folks for years, journal, take up a practice of contemplation and do a lot of hard looking at yourself and talk with safe people.
BTW, the "just confused" thing is a BS cis-phrased judgement. You are where you are, period. Instead of judging yourself and thinking that you must have an ultimate answer now, take your time and do the work of getting to know who you really are. Be kind to yourself and give yourself the support you need to know really who you really are.