I might have stds?

So I'm pretty sure I caught something from the guy I had sex with, he was only the 2nd person I've ever slept with and I'm still only 18, now if I did catch something I'm worried about never being able to find anyone to call my own for life :( has anyone here ever had or current live with an std? If so how did it affect you and your relationships with other people and finding a romantic relationship