This is very disturbing. There is no excuse for witholding basic blood tests because you are young. It is the first thing that should have been done.
FBC including thyroid function and liver function, iron including binding (TIBC) AND CRP is a must. Insist.
Either at the same time or following tests they need to refer you for an ultrasound that you can afford. Ultrasound should capture full view of lower and upper abdomen. They were stungy to begin with now they may as well do their job. Something is ruining your quality of life and compromising your overall health. It may be something simple but just leaving it to see how it develops is not acceptable on account of your age.
Bring someone older along with you if possible. This is really bad practice on your doctor's part.