cdc,sounds like you may have done to much to quick,depending on how long you've been training i personally would stick to 3 easy sessions aweek and try to do a longer run on the 4th,6-8 miles,also depends very much
if you have a goal in mind ie.10k or a 1/2m.Build up slowly,i have been running for 30 years and rest days are very important to let the body recover,get aggod endurance base and take it from there,and most importantly listen to your body,good luck.