What Causes Severe Pain After A Shoulder Surgery?

Hi My question is . I had surgery on my shoulder for a few bone spurs and clavical and a cpl other things in the shoulder .This has been since sept 27th . How long does it take the joint to heal up I have been up for 3 nights with bad pains in it hard to move without pain I cant get into see my dr. They have me on percocet 10/325 sometimes they just do not work at all why is that .ait is excruciating pain .I am in therapy for the shoulder twice a week .I had surgeries before but none of them have made me feel like this it seems it has took 10 years off of me .Its hard to handle it . If i had it to do over would never had it done . please reply .