Post Surgery ACL. What should be done?

Its been 4 months post OP, I can walk normal, climb upstairs(sometime sudden pain on knee side), Can't walk downstairs properly. My knee is still swollen. when my knee is tired, it feels like it is coming up over bone(knee clicks a lot- not an issue) but suddenly knee coming upwards scares me. I am doing my excerise, can bend but not beyond 125 degree. full extension, but not exactly like my normal non-op leg. what should be done ? I use theraband to do excercise,walk 2 K.m. daily normally. Also for QUAD excercise to bend leg while standing is 90 degree. while sitting can easily bring my knee to 120 degree. while lying on my back its 110 degree. Pain when i stand up after sitting for 10 minutes, knee clicks a lot, feels the stitches wound pain. what should be done ?