Male high singing problem

Hi guys..I'm a male 21 yrs old and have a problem singing high notes...I started singing when I was 18 and so it's been about 3 years.When I first started singing I couldn't even hit A3 and now through youtube and some research I can hit upto C#5 and even D5 sometimes.It's not head voice because I have no idea how to do it and not falsetto because it's loud and heavy.Also my falsetto is pretty weak cracks at C5.And hitting those high notes does not hurt but I can't get used to singing on those notes.I feel weak all of a sudden....
So my question is will I be able to sing those high notes properly or am I just pushing it ?
And I've no idea if I am a baritone or not...
Sorry for the long part.I just wanted to make it clear..
And I can't go low as what I used to when I started.Before power D2 - now weak and breathy E2 almost feel like puking sometimes...
And sorry again I used take classes but where I live no one teaches how to go high...So guys ??