Why are my ankles swollen?

My feet, ankles, and calves are very swollen. The Dr. put me on Lasix today. My blood pressure has gone up for some reason. I feel like an ice cube. I went to the Dr. last week and he put me on thyroid medicine due to some blood tests that I had done the week before. I went back to see him today. My skin is dry, yet the Dr. said I am over hydrated. What do I do when I get thirsty if I am over hydrated? I also have very low energy and I can not focus on my school work, so the Dr. wrote a script for Adipex 37.5 to be taken once a day in the morning. Today after I took the first dose of Adipex I can tell you that I was able to focus much better. I am a 44 old male, 6'0 tall, 223lbs. with clothes on but last week I was 217lbs. I am sure the extra water has caused the gain in lbs. This is our second week back at school. Could the couch potato effect have caused the sudden changes in my body ? (three and a half weeks off from school.) Pardon me, but I have to go pee once again.