Hi OP, was your surgery on the left or right leg? And therefore is the pain on the outside or inside of the leg?
I’m not a specialist, but it sounds to me like your muscles are very weak. If the pain is on the inside (medial) side, close to the tibial incision, it could be the hamstrings, or the VMO, or likely both.
Are you seeing a physio? If so, I would suggest checking with them if that’s the case. They should be able to reassure you, but also to give you exercises to address those issues without endangeringyour graft. I can’t stress enough just how important it is to have a physio who has experience of ACL rehab and to follow their protocol exactly - listening to both what they tell you to do, and NOT to do! The shrunken appearance of the operated leg is because of muscle wastage after surgery and is completely normal. Only consistent physio and rehab can rebuild it though. My surgeon always says the surgery is 20% of the ACL recovery, and the rehab is the other 80%. Good luck and keep us posted!