As well as oral acyclovir, you may well need pain killers such as paracetamol. The main question though is, how do you know it is herpes zoster (shingles)? Have you already seen a doctor? Oral acyclovir usually requires a prescription and it is only effective if you start taking it within the first three days from the first symptoms.
Although uncomfortable, it will usually clear up within 7-10 days without treatment. During that time, you will be infectious to people who have not previously had chicken pox so you should be careful to keep the sores covered with light clothing.
You can wash the sores with an antiseptic soap but it is best to ask at a pharmacy to see what is available in your area.
It is unusual to get more than one outbreak of shingles and it usually occurs about 40 years after chicken pox.