By using a condom, that is the preventive care that you need. Really.
In dealing with STDs or even HIV, we encourage sexually active people to be tested from time to time. That is like a health check report card. If there's any problem, get treatment.
Please do not self-treat, by getting antibiotics and etc. Taking medicines without supervision will create drugs-resistance problem.
Bottom line: You used a condom. A condom protected intercourse protects you from HIV and most of the STDs. You are safe.