Make my theme responsive or?

Heey,

I would like to have my blog and galleries integrated to my web-page like somthing like this.

The problem I ran into when I try to do this is that this theme from Graph Paper Press is not responsive and because of that it don't look good on some screens.

Please! Anyone have any idea what I can do to make it work?
Or do you think I should start over with a responsive theme?

I really would like to keep me theme and the vertical menu I have.

I'm open to any solution. The most important thing is to keep my menu and have a responsive theme!

I had this problem for over a year now and don't know how to fix it...?

My knowledge in HTML and CSS is very basic.

Thanks.
k