It sounds a lot like hip displasia. In dogs, the problem almost always appears by the time the dog is 18 months old( 1 yr, 6 months) The defect can be anywhere from mild to severely crippling, and can eventually cause severe osteoarthritis. It is most common in German Shepherd Dogs, Labrador or Golden Retrievers, Rottweilers and Mastiffs. It is known to be hereditary but can appear on it's own as well.There is no complete cure, although there are many options to alleviate the clinical signs. The aim of treatment is to enhance quality of life. Crucially, this is a congenital condition and so will change during the life of an animal, so any treatment is subject to regular review or re-assessment if the symptoms appear to get worse or anything significantly changes.
If the problem is relatively mild, then sometimes all that is needed to bring the symptoms under control are suitable medications to help the body deal better with inflammation, pain and joint wear. In many cases this is all that is needed for a long time.
If the problem cannot be controlled with medications, then often surgery is considered. There are traditionally two types of surgery - those which reshape the joint to reduce pain or help movement, and hip replacement for animals which completely replaces the damaged hip with an artificial joint, similar to human hip replacements.
Your dog seems to fit the criteria to be at risk for hip displasia. You can take him to a vet. That's all you really can do to help him.
If you can't afford to take him to a vet, maybe you should consider finding him a new home where he can be properly taken care of. Sounds like he is suffering to me and needs medical attention, he is not even 2 years old, how long do you think he can go on like he currently is? He is not going to magicly get better, please for the sake of the poor suffering dog. TAKE HIM TO SEE A VET!!!
Have to agree with reddog. He must be in pain and you definitely don't want him to be suffering. Unfortunately, pet ownership can come with Vet bills and maybe it was not the best of times for you to have a pet. Hey, I've got a sick Greyhound here that I just put out almost $500 on and we still need more testing done. I don't know what to tell you. Maybe you have a Vet in your area that would let you make payments? Please try to work out something to get the dog checked.