Age is probably a factor and you'll probably explode when you hit your prime at about 21 ^^ I can press just slightly under that, but I'm taking hiatus from body building atm to pursue long distance cycling for the summer.
I bet if you dedicated a day to just chest and triceps you would hit 45kg in just a month
![Grin ;D](https://boutcheetah.zylongaming.com/Smileys/fugue/grin.png)
The gym right across from my school is MetroFlex which is the home of CT Fletcher & Mike Rashid and I've seen them train people my age from decent to passing 45kg in just under 6 months! It's truly amazing.