Help??

[thatbox]

Hey All,
So i'm quite chubby and stocky (not muscular) but I've recently been trying to build muscle in my upper body, i've got one Dumbbell with about 4Kg on and I have the ability to add another 4Kg. I've been lifting that with Bicep Curls and Hammer Curls (across the chest). I've also been doing chair dips with my feet on my bed and my hands on a chair, bending my arms to about 90 degrees. I feel happy this is building my triceps but my push ups aren't getting better, when I do a proper one my lower back hurts and my chest. I'm hoping I will get better over time. Thanks for reading and if you could offer any tips it would be much appreciated!

Thanks!
-ThatBox!

[JamesSuperBoy]

Maybe start with push up just on your knees not prone.
Pushups work the back and abs as well so if they are not strong you strain.
do the chair dips with 2 chairs.

try a few push ups same way feet on bed hands on chairs,