I have severe pain in my tooth, what should I do?

Q.
My mower tooth had a hole about 3 years ago hole was on the side rather large had a dentis fill it with white hard stuff and it was more a less good till the last few weeks firstly I had very bad pain from the tooth after about 3 days I had to go to the dentist and he X-ray my tooth in question and said its inflamed all he did then was give me a weeks dose of antibiotics 500 ones I couldn’t eat for days couldn’t even touch the tooth even eating watery soop that was painfull after about 5 days after I could eat some soft things all was getting better and now three weeks on I grinded my tooth slightly and I heard/felt a type of cracking sensation but no pain few days after I couldn’t put much pressure on the tooth again enough to eat but it’s there sort of thing I’m just worried I’m going to eat something that’s going to crack the tooth and how painfull would that be ?? Please give me some advice on what could I do apart from go to the dentist. Many thanks