It sounds like you are in recovery from a long struggle with anorexia - good for you! Regarding making up for lost time, approximately 17 to 18 percent of adult height accrues during puberty. The increase in height affects both your body and your limbs. The limbs grow faster than the body (maybe you have heard the saying "all hands and feet."). In later puberty, however, the growth spurt is primarily in the body. The timing of the growth spurt varies by gender, occurring approximately between ages 9.5-14.5 for girls. A couple of years later growth plates in bones close and bone growth stops.
In people with anorexia, the time of physical maturation and growth can be delayed which means growth plates can stay open a little longer. However, it seems unlikely that at 20 you could "catch up." The way to find out for sure is to X-ray the wrist, called a bone age scan.
If growth plates are closed further growth is not possible, which is not something you would want to happen!
Let your doctor know your concerns about your growth. Your doctor will be better able to understand where your growth should be and discuss if there is anything else you can or need to do. If you do not have your own doctor and live in northern New Jersey, you can contact the Eating Disorder Program at Atlantic Health System for an appointment by calling 908.522.5757. If you live outside of this area, log onto the National Eating Disorders website for information and resources.