Had knee pain/swelling for a month, after that I had bilateral joint pain wrists, shoulders, hands since 15y/o.Now the bone in fngers is larger. Why?

Could be many. This is more complex and needs to be evaluated by an Orthopedic doc or a rheumatologist- likely need X-rays and blood work to make sure you do not have a metabolic bone disorder- can also be related to statins.
Have it evaluated. Arthritis can be genetic or it can be due to gout, infection or chronic wear and tear. It can result in local areas of inflammation within the joint.