Positive for chlamydia negative for everything else- open sores

Hi, I just received my std test results back. I had painful urination. I was positive for chlamydia but negative on everything else. I also noticed in the last few days that I have a few open sores on my foreskin that are painful esspecially to water and to the touch. I am uncircumsized. And masterbate often when not having sex but haven't for over a week now due to the painful urination and the recent sores. Does anyone have a clue what this could be or if I should be concerned?