Some things that your not considering about mary jane are:
Loss of balance, a big one especially when working legs and back; squats, dead lifts etc.
Impairment of cognative thinking, problem solving and memory
Increased risk of heart attack
increased risk of chronic cough and repritory infections , this is especially worrisome if you are a social smoker and use pipes, bongs, and/or share joints.
As far as your reason for use" when i feel sick and have a sore throat" if this is happening more then 2 times a year maybe you need to be looking for the under lying cause.
If your just looking for someone to say oh hell its ok everyone does it, your probably not gona get that here. And please dont think I'm judging you because I'm not. I smoked weed, drank, smoked ciggarrets a and a lot of othrr stuff that I'm not not proud of, the day I'm not proud of is the day i quit all of it and decided that i wanted to be around to see my kids and my grandkids and maybe even great grand kids grow up. You gota make your own decesison on this but if you have more questions let em out or pm me if you want with questions you dont want public. In the words of Dr. Laura "Love Now go do the right thing"