Swollen ankle on c25k :(

Was absolutely fine until I tried w4. (I know pathetic!)

First my knees puffed up. When they went down I went out again and now it's my ankle! So frustrated right now!
Feels like a sprain but I didn't go over on it or anything. What could it be?
Am I just unable to run you think? I'm only 37 and could do a 8 min mile on a treadmill no problem about 10 years ago, but I feel like I'm falling to bits now lol!!!!