Hi it has been a bit since I posted. I have not made any progress yet unfortunately I have tried stretching, running, exercises. I believe you that my core might be the center of the problem but I cannot work my abdomen muscles. When I do situps and whatnot my hip flexors seems to do all the work and get tighter. When I try to stretch my tight hamstrings/ankles they seem to just get tighter and not give in.

Any advice on how to get a good core workout with a hip flexor problem?