By definition, a disc herniation is the result of a degenerative disc so this disc will of course be degenerative. Stiffness is not unusual after surgery and I would agree that an aggressive physical therapy program is necessary to restore range of motion and increase strength.
Do not worry about what this level looks like as your focus needs to be rehabilitation. (This is assuming there is no infection which would be unusual). I see severely degenerative discs all day long in patients without symptoms so start rehab and increase your strength.
Donald Corenman, MD, DC is a highly-regarded spine surgeon, considered an expert in the area of neck and back pain. Trained as both a Medical Doctor and Doctor of Chiropractic, Dr. Corenman earned academic appointments as Clinical Assistant Professor and Assistant Professor of Orthopaedic Surgery at the University of Colorado Health Sciences Center, and his research on spine surgery and rehabilitation has resulted in the publication of multiple peer-reviewed articles and two books.