If the pain is severe, it is better to consult a dentist. As you also have a gap forming in between teeth, it can be fixed by a dentist only. However I am listing down some home remedies which I normally do when I get tooth ache.
1. Brush your teeth thoroughly and rinse it off. It will give you a little relief. You can rinse your mouth with warm salt water.
2. Apply clove oil or bite a clove by keeping it on the affected tooth. It will slightly pain but you will get a relief.
3. Crush a garlic clove and have it placed on the teeth which is hurting. I have done it once when my pain was severe and start to pain even more but after few minutes it started coming down and it became bearable.
4. Take ice cubes and cover it with a towel and place it on your cheek near the affected area. this really helps in most cases.
5. Clove oil mixed with olive oil and salt will also help. Dip a cotton ball into the mixture and have it placed on the affected tooth.
6. Chewing a ginger piece also helps at times. It gradually brings down the pain.
7. Try not to eat with that side for 2 - 3 days, once the pain is gone, you can slowly start using that teeth of yours. Also make sure to brush your teeth often. While brushing, use salt and black pepper powder.
If nothing of the above works, please do not waste time rather take an appointment with a dentist and get it fixed.
"Do not give up, things might not favour you always"