Julie, I am so sorry to hear that you've gotten an STD. You need to advise your h of this information, as he is this little gift around to others. If you've not been w/someone during that time period, it most likely was your h that gave it to you.
The bottom line is this...take care of yourself, take the meds for the STD and do what you need to do to get your diabetes under control. Stress has a way of hitting our weak spots in our bodies. So, be kind to yourself and start relaxing a bit more.
I know that you are furious right now and I do not blame you, but you do need to tell him so that he can be tested and he will definitely need to tell all of his partners that he's given out the gift that no one wants.
Please, please take care of yourself.
Sit quietly, the answers will reveal themselves when you least expect them to. The past is gone, the present is a gift and you need to focus on today, allow the future to reveal itself when it is ready.