Taking Acylovir for herpes and it seems to me that the vaginal blisters are getting worse?

It takes 2-3 days. If this is a new herpes infection and you've only recently started treatment, you may just need to give it more time. It takes 2-3 days before improvement. If it's been longer, you might need a higher dose of acyclovir, or perhaps switch to valacyclovir. Contact the doctor who diagnosed you and prescribed the drug. That's the person you should be asking questions like this. Good luck!