Um, yeah, if you went to the doc and found out you had chlamydia, they would have given you the prescription for the antibiotic to get rid of it.
Did you get tested for the other stds? Keep in mind that some stds don't show up immediately, some not for years and you could be giving your husband other things.
You need to tell him regardless. Even if you could get the pills for you and for him, you can't just slip them into his drink. It is an antibiotic to be taken orally and he would have to know he was taking it.
You need to tell him/talk it through and both get tested for hiv and other stds. And then make sure you get your paps annually because you are now at a higher risk for cervical cancer.