I've been taking doxycycline for a year and a half and have gaine...

I've been taking doxycycline for a year and a half and have gained about 25 pounds because of an insatiable appetite. I couldn't figure out why I was always so hungry, but no matter how much I eat, I always have an empty feeling in my stomach. I also have severe headaches on a regular basis and blurred vision. Just recently, my doc changed my dosage from 100 mg once a day to twice a day and I was outside in the sun over the weekend. Even though I was very diligent with the sunscreen, my face got very burned and my lips got a strange tingling feeling (like when your foot falls asleep). Then my arms and hands got a cold tingling feeling like water was hitting me, but it wasn't. Today, two days later, my face is still really sun burned and my hands still have a numb, cold feeling, I'm guessing because of exposure to the sun.