Physically impossible for me to do head voice or falsetto (Male)

[Brew7461]

Basically I no longer can sing in head voice or falsetto. A few years ago I was able to sing in head voice I believe (still don't really know the difference, I just know I can't make high pitched sounds) but it was very difficult even then and the last time I was able to do it like that was about 3 years ago. The last time I was even able to make any kind of sound in that area was about last year but I only sang one phrase then my voice cracked. I can't even do a "woo" or scream. I've tried looking this up but they all say to just go higher and it will come naturally but when I get to my highest mixed note (D5-Eb5) I just simply can't go any higher.. I turning 16 soon so could it just be my voice is still developing, bad technique or is it damaged?

----- Had two things to ask but thought I would just keep it in the same post 

Also another thing is I am not new to music I just want to be able to sing decently to my favorite songs but my voice is very soft and weak and I hate it especially in mixed voice, I have a soft tenor sound which I can make a little bit more powerful by singing louder but my range is E2-D5 (comfortably F#2/G2 - D4) anything below F#2 I can only sing with a lowered larynx, anything above roughly G4 is raised larynx and mixing which sounds super whiny and starts to hurt after a while making singing with male singers extremely difficult. I know this isn't much to go off of and is kind of all over the place but any advice would be greatly appreciated!