Hi there. Thank you for the question. It is apparent that you are worried about your condition. Based on what you have mentioned, it is apparent that you are infected with syphilis stage 1 as there are ulcers on your penis. It is advisable to consult a doctor regarding this problem.

Treponema pallidum is the bacterium which causes syphilis. Transmission through contact with an infected person's sore during sexual activity is the most common route of transmission. Syphilis symptoms comes in stages and it is divided into three stages. As you have mentioned, the first stage of syphilis is usually presence of small sore, called a chancre and it appears at the spot where the bacteria entered your body. It is usually painless and it resolves in three to six weeks.

After the first stage, there will be a second stage of the infections. At this stage there will be rashes that begins on your trunk but eventually covers your entire body including the palms of your hands and the soles of your feet.

Most commonly used antibiotics for syphilis is Penicillin. This medication will be given intravenously for two weeks. If you are allergic to this medicatiions, you will prescribed with doxycycline, azithromycin or ceftriaxone. It is crucial for you and your partner to complete the antibiotics course to prevent the recurrence of infection. It is also advisable to practice safe sex or abstinence for the time being.