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.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 ??