I'm currently in the same situation. Though I'm only 14 I am VERY prone to colds, sometimes I will get multiple in one month. I've got a lot of techniques, but for soreness? Sudocrem. It's a nappy rash cream here in the uk that works wonders, also really seems to help my eczema! If you don't have that brand where your from look or ask at a chemists for Zinc Oxide cream. Hope this helps!
If you have any the EOS lip balm you can use it to stop some of the soreness. I'm suffering from a cold and been having the same issues with my red being red for using to many tissues. So my mom told me to use a little bit of EOS lip balm to take some of the soreness and redness away and it has worked. You just have to apply it a bit after u sneeze and blow ur nose. But it does work