Exercise and keep going!
Continue with normal activities as far as possible. This may not be possible at first if the pain is very bad. However, move around as soon as possible, and get back into normal activities as soon as you are able. As a rule, don't do anything that causes a lot of pain.
In the past, advice had been to rest until the pain eases. It is now known that this was wrong. You are likely tom recover more quickly and are less likely to develop chronic (persistent) back pain if you keep active when you have back pain rather than rest a lot. Also, sleep in the most naturally comfortable position on whatever is the most comfortable surface. (Advice given in the past used to be to sleep on a firm mattress is better than any other type of mattress for people with back pain).
If you need painkillers, it is best to take them regularly. This is better than taking them no and again just when the pain is very bad. If you take them regularly the pain is more likely to be eased for much of the time and enable you to exercise and keep active.
Some people visit a physiotherapist, chiropractor, or osteopath for manipulation and/or other physical treatments. It is debatable whether physical treatments would help all people with a prolapsed disc. However, physical treatments provide some short-term comfort and hasten recovery in some cases.
Surgery may be an option in some cases. As a rule, surgery may be considered if the symptoms have not settled after about six weeks or so. This is the minority of cases as in about 9 in 10 cases; the symptoms have eased off and are not bad enough to warrant surgery within about six weeks. The aim of surgery is to cut out the prolapsed part of the disc. A specialist will advise on the pros and corns of surgery, and the different techniques that are available.