What you are taking is to support and possibly rebuild joints that have had lots of wear and tear. However, the pain is from inflammation. For pain, you want products that have potent antiinflammatory properties such as tumeric, ginger, and bromelain. Omega 3's (fish oil) and antioxidents are good too. All these affect pain at the site. 3-HTP has been shown to help with pain via the central nervous system. Dosages depend on the individual: history, severity, etc. As you know, supplements don't tend to be immediate. Three months of disciplined supplementation is a fair shot to determine if it will help. You can buy these supplements at health food stores.
On of the best supplements I've ever seen for pain and recovery is Xango, which is made from the mangosteen fruit and contains a category of nutrients called xanthones. you can go to pubmed.com and search for mangosteen or xanthones if you want to read research abstracts. You would need to find an independent distributor to try it.
It's a big deal not to eat junk if you have chronic pain. Avoid trans fats like th plague.