so you find yourself in 272 bc....

[Azathoth]

Unfortunatly AP, you won't be able to accomplish all that because:

a. You need acid for nitroglycerine (why would you want it anyway?)
b. There's no industrial base so mass-producing anything will take decades.
c. Sulfuric acid as a wall defence weapon? With Greek Fire and gunpowder available? That's kind of, uh...
d. How are you going to use, or even obtain, oil? Conquer the Arabian Peninsula, and then you have to actually build all the engines that use oil, which I don't think you can do.
e. Maybe you can vaccinate against smallpox, but the plague? We don't even have a vaccine for that now.

In short, your dream could be accomplished by the time of your grandchildren, but probably long after you are dead (unless you are the Yankee in King Arthur's court on steroids).