Small Bump In Throat, Comes And Goes, Hurts On Swallowing. What Is It?

I first noticed a small bump on the back and to the right of my throat, it hurts slightly to swallow when its out but the strange thing is it goes down and away for days at a time and then comes back for no reason. Ive found useing mouth wash when it does come out will make it go down and then disappear for a few days before it comes back again out of the blue. I brush and use mouth wash every day so not sure what the problem is, I dont have a fever or any pain swallowing when its not out. Ive stuck my finger in and touched it and is simply feels like a small hate to say pimpal but thats closest thing I can think of to the feel of it, when it goes down its completly smooth again and I dont even feel a slight trace of a hard surface or bump there, till it comes back. Its grows to its full size within mins and normaly happenes when Im eating as if the food may be irratating it.

I dont have the money at the moment to go to the doctor so I hope someone can help, lease put my worries to rest. Im a 30 year old male if that makes any differance.