Do you have chronic constipation? Did you do massaging yourself? Do you have severe bloating and distension? Is there any tenderness in the abdomen? Do you have nausea? Was the initial problem only constipation or started with the mild pain abdomen?
Undiagnosed pain abdomen, lump/swelling with nausea, bloating and your other symptoms warrant quite a caution. In your age group, these symptoms point out to various thing which include appendicular lump (acute appendicitis), ovarian torsion, Meckel's diverticulitis etc. In a patient who has chronic constipation, fleet enema can be given but with your symptoms, enema should be avoided till a diagnosis is made. ideally you should get yourself examined by a physician as it would give clue to the diagnosis and would also tell the need of investigations like an ultrasound. You can consider going to an urgent care clinic or ER. At home maximal what you can do is to try a suppository to see, if helps you, passing motion and relieving your symptoms completely. If not, there is not much you can do at home and may complicate the condition.
Please feel free for your follow up questions.