Milly,

Watch out! I did what you are doing now when I was 19 visiting Australia and the Philippines and never looked back - I've now spent most of the last 10 years working or travelling overseas - the last five in Singapore. Don't spend too much time there - you are better off in Bangkok - but you should spend some time checking out the nightlife with the locals who love to party!

One thing to remember if you have a bad experience is the power of perspective - is this something that I am going to worry about in a year's time or five years' time? Is it something that I am going to let spoil my trip? Nope is the answer in most cases!

Have a great time!