Based on your age your tooth is most likely loose from periodontal disease.
Periodontal disease (gum disease) is a chronic, low grade infection of the gums surrounding the teeth. It is caused by bacterial plaque which lives in your mouth and attaches to the surface of the teeth both above and below the gum. If enough plaque accumulates under the gum, and remains for enough time, an infection will start. This infection starts in the small spaces between your teeth and gums. The gums react to this process by swelling up and loosening their grip around the individual teeth. This loosening opens up deeper spaces between the gum and tooth allowing for more debris, plaque and food to work their way into the spaces. As the disease progresses, it slowly dissolves the bone around your teeth and, as it shrinks away, the gums follow. Many times, the patient is unaware of this disease because there is no pain involved until it gets to the advanced stage. Other symptoms of periodontal disease are bleeding gums (when brushing, or spontaneously), receding gums and bad breath. Many times, by the time an individual notices these symptoms, the disease has been active for quite some time, even years. Periodontal disease can be treated and many of the symptoms can be reversed. You need to go to a dentist that specializes in this disease, namely a Periodontist. He will diagnosis the severity of your condition and recommend treatment. Many times this disease can be treated with a thorough dental cleaning and root debridement.
In the case of this one tooth, however, the Periodontist might bond it to the adjacent teeth, essentially splinting it to it's neighbors. This will immediately stop it from moving, but more involved treatment will probably be needed in this area of your mouth due to the advanced bone loss. Once the plaque, infection and inflammatory toxins are removed from between your teeth and gums, any bad breath should go away, your gums will tighten back up and any bleeding should stop. Keep in mind that periodontal disease can not be cured; only treated. After the initial treatment from the Periodontist, you will need to return a few times a year to him/her or to your regular dentist for regular dental cleanings. This will keep the disease at bay and prevent it from escalating to the degree that causes bone loss and further gum shrinkage.
There is no home treatments that will treat and tighten up a loose tooth.
I hope you find this information helpful.
George McKee DDS