Do I have a UTI?

I've never had one before but last night I masturbated and then woke up and the end of my pee burned a bit. Since then every time I go for a pee it always burns at the end (not at the beginning or halfway through).

I would rather not have to use antibiotics for this but will go to the doctor if it gets worse. For now I have no other symptoms just the burning at the end for a couple of seconds.

I've just taken 1000mg of vitamin C which I read taken daily will help to get rid of it and also grapefruit juice extract? Will I be alright?