Thanks for the question and concern. It is very unfortunate to know that you are having such a problem at a very tender age. There are a number of sexually transmitted diseases on std list which can be a matter of concern for you. The gonorrhoea is the most common sexually transmitted infection incepted through physical contact. The symptom is painful blisters and itchiness. The herpes is another one in the list that has got some blister like formation in the genitals. Trichomoniasis is also one of its kinds having excessive frothy and greenish vaginal discharge. This may be the infection you have got. The trichomoniasis has got increased risk of HIV associated with it. It is advised to cut down the levels of alcohol intake during the periods of treatment. Plus the intake of antibiotics can combat the infection at a good rate.  Practising safe physical intimacy is required. Use of good quality protection is highly recommended to avoid the infection. Trichomoniasis can get transferred to male counterparts as well, so it is advised to prevent sex during the infection. Also the use of medicated soap and sterilised wool to clean up the area shall be encouraged.Take a good care.