Hey all, thanks so much for all your comments / suggestions / advice.
I've been to see a physiotherapist and Posture / Mobility therapist, both had interesting results and will work on this from different points of views. The pain isn't actually in my coccyx itself but the surrounding muscles, which is why the sciatic pain feels like it's there in my left leg hamstrings plus cramp occasionally in the same area. Both have said that the laparoscopies, increased exercise, and dislocated kneecap recovery will have resulted in tighter muscles around my back area, this has causes referred pain.
Physiotherapist - will look at my lower spine as it appears fixed - it's not as flexible as my upper spine; most likely a "protection" thing the body does while my core was healing from the surgery. She's given me exercises to improve my glutes which in turn will help my lower back, as well as her manually manipulating the fixed muscles.
Posture / Mobility therapist - has said the surgeries and kneecap dislocation has resulted in over compensation of my piriformis muscles, which have become inflamed and tense therefore putting pressure on the sciatic nerve and coccyx (not true sciatica as the middle spine is fine). He will work on moving and applying pressure to my piriformis to loosen muscles, plus exercises to activate my core as surgeries have resulted in it not really functioning.
This should all help my flexibility of my lower back, loosen muscles and improve core. The coccyx pain will go when the muscles are all sorted. I didn't realised the surgeries would affect my back muscles but it makes sense.
Yay, getting somewhere