first of all, the fact that your playing tennis with not too many problems is a very encouraging sign.

the pain in your shins? could be sensitisation of nerves from the area the incision was made. you need to actually introduce different textures and temperatures etc to this area to desensitizae the area ie let the nerves get used to feeling different things again. if you havent been doing this it may be why its so sensitive still.

crunching/sharp pain in knee? acl rconstruction +/- meniscal repair etc is a big surgery and it along with the period of immobilisation and partial weight bearing on crutches etc afterwards can lead to joint stiffness and muscle imbalances etc that may cause all sorts of symtpoms.

have you been back to your surgeon, is he happy with how things are going?

i had my acl repaired with both menisci repaired in junel ast year and i just played my first match back last weekend. 10 months later. people differ in their rehab and return to sports after surgeries. some basketball p;ayers in the us are back inside of three months!

provided your acl is intact your knee should be stable, which is the goal of the surgery. it is a matter of slowly progressing strengthening, balance and sport specific activites at a pace suited to you until you are ready to return to contact sports involvong twisting etc.

its certainly not too late to go to an experienced physio who deals with acl rehab often and start putting a plan thats appropriate to you into place and setting a goal for maybe to play in another six months or maybe earlier.

dont rush back and just take each step as it comes. certainly dont rule outplaying football again.