NDRN, it sounds like we're experiencing very similar tracks of 'progress'. I also am having back issues as I re-learn to walk and often feel dissatisfied with the pace of recovery, particular ROM. I chastise myself for lacking the patience I feel like I should have more of as well. I certainly expected to be a lot more functional at this timepoint. Mentally, it feels very bipolar. I have good days when I'm thankful that at least I don't have the debilitating, searing pain of pre-op; and then bad days when the sun is shining and I just want to be able to get out and be 'normal'. I see occasionally glimpses of what the future normality will look like, but it comes and goes.
Not sure if this will help you, but I've noticed that taking days off from the exercises actually helps a bit in my progress: I tend to have pain and swelling and easily overdo things, especially when trying stretches, and they end up setting me back. Thus, taking off days seems to give my joint time to 'calm down'.
Hang in there, we'll make it, eventually. I have to believe that and keep forcing the thought upon myself to prevent going down a darker path. Take care!
ps - I'm still taking pain meds 3 or 4 days per week.