It is hard to tell what the little red lumps in the vagina, that grew and multiplied recently, are without seeing them. However, certain assumptions can be made.
Red lumps detected on mucosa (just like in the vagina) are usually a sign of infection. Whether the infection is acute or chronic and whether it is caused by bacteria or a virus cannot be determined without an additional examination.
However, if the bumps are multiplying, you might have experienced genital warts that have not developed to their full size. Genital warts are a highly contagious sexual disease caused by types of the human papilloma virus. They are usually located in and around the vagina, or on the cervix (opening of the uterus). They are often located around the anus, too. In men, genital warts can be found on the shaft of the penis as well as on the scrotum and around the anus.
Genital warts are a result of decreased potency of the immune system, which is not able to fight the papilloma virus. The transmission might have happened even many years ago, because the latency period (during which there are no symptoms) might be very long. The treatment includes podophyllotoxin solution in a gel or cream. Liquid nitrogen cryosurgery is a treatment option, too.
You might want to visit a gynecologist for a visual physical examination. The doctor might decide to take a vaginal swab to clearly identify the cause for the red lumps in the vagina.