I have been in back, hip&pelvis pain for 1 month since I got injured. I don't know if it is from the l5-s1 bulging disc or 50-75% ddd? Will it heal?

it likely from just. Muscular sprain/strain. Those can be very painful, but good news is that they all heal well eventually. The disc bulge and ddd is normal findings on your MRI -- it happens in everyone, and continues as we get older.