Hi, I Have A Grade 1 Spondylolthesis Of L5/S1, Bilateral

Hi, I have a grade 1 Spondylolthesis of L5/S1, bilateral pars defect. X-rays & Ct scan performed. I'm having an MRI today & the Orthapdedic surgeon wants to see the discs. Pain is worsening, I take Panadeine Forte daily but gives little relief. I have lived with lower back pain for years but as its getting worse I need some other relief. Im 35yo.
Im booked in next week for pars injections & desperate for this to relieve pain. Is there any other pain medication I can take that is better than Fortes? Doc does not think it is affecting the nerves, i just have extreme lower back pain, worst in the mornings but remains all day. I was a very sporty person, running, gym, weights but told I can no longer do anything high impact/ heavy weights etc. Any advice, much appreciated.