the prongs on my ring have loosened and now my diamond is wobbly... what do i do now?

The best thing to do is to take it to the nearest professional & trusted jewellery store, or your place of purchase for some small repairs. The repair is not a difficult job, and if you have not damaged the ring, then most jewellery retailers (if they sold the ring to you) would do this for you free of charge. 

The first step would be to return your ring the manufacturer to have the claws tightened. If this is not possible then a manufacturing jeweller will be able to either tighten the claws themselves or they may wish to have their diamond setter do it. Some jewellers (like EverettBrookes) provide lifetime warranty on their workmanship and provided your ring has not sustained an impact this would generally be covered under that warranty. If there has been some impact damage their may be a small cost to make any necessary repairs, tighten your diamond and in the case of white gold, rhodium plate. There are a number of reasons a diamond can work loose and we recommend having a jeweller inspect to advise the best course of action in your case for your ring. It is best avoid wearing it until it has been inspected and secured.