Mobile/Tablet Optimisation Issue

Hi, pretty new to this so would appreciate the help!

I am trying to optimize my site for mobile / tablet but have been having some major issues. When I design my site on the different responsive modes, it changes the design on the different modes which has caused hours of reformatting my site.

I have resulted to going onto tablet mode – and duplicated my elements, hiding the original on the tablet and then hiding the tablet version on mobile / desktop. However this isn’t a long term solution to my problem going forward.

I have also tried to download wp touch and use that to create my mobile site – but im having issues with the header sizing.

Any help would be massively appreciated!

The page I need help with: [log in to see the link]