Molluscum contagiosum is a completely benign infection. There are no complications and it always goes away. I'm not saying to ignore it and I understand your concerns, but don't lose a lot of sleep. It is a trivial condition.
There are uncertainties about genital area MC. It is seen pretty frequently in STD clinics, and most cases appear to be sexually acquired. On the other hand, dermatologists also see many cases, often in people in whom sexual transmission doesn't seem likely. Most cases in men involve the pubic area, lower abdomen, or upper things; as you can imagine, sexual transmission may not be necessary for such cases. But occurrence on the penis itself almost certainly requires sexual exposure.
Other than sex, the best bet is contact with young children. Most cases of MC occur in toddlers, who get it by salivary contamination, such as mouth exposure to shared toys in a daycare setting.
As for your sex partners: Most likely you caught it from whoever you were having sex with in the 2-3 months before the problem started last October. You should speak to that person so that she (assuming it's a she, not a he) can get checked. For your current partner, she might not even be susceptible. If she had it as a child, she probably is immune to catching it again. But even if she has noticed nothing wrong, it would be wise for her to visit her provider to check for MC lesions and get treated if any are found.
Treatment of MC consists of removing or destroying the lesions as they come up. Common methods are currettage (i.e., for a provider to scrape them off, which causes much less pain than you might think); to freeze them; or to use certain medicines, like imiquimod (trade name Aldara) -- but that's much slower. Sometimes providers teach patients to treat themselves by pricking the lesion and then expressing the hard white core. But please don't do that unless/until a provider recommends it after personal examination. If you haven't done so, I suggest you visit a dermatologist then follow his or her advice.
Whatever you do, don't worry about it. Although it sometimes takes a few months, eventually the immune system kicks in and the lesions will stop recurring. And then you will be immune to new infection.
Good luck-- HHH, MD