You are probably training too hard. Try to start with 3 times a week, if you can 30 minutes but at low HR, about 70-75% of your max HR. If you don't know it, go with 220-age.
Your training should be at around 140bpm... walk if your HR is too high.
I would then run longer than 30 minutes, but no more than 3 times a week for at least some months.