And sometimes they don't understand me if I use a wrong tone somewhere. It's so difficult sometimes... :-/
My wife has learnt English since about 3 years of age. So we don't have any problems there.
But NZers have a nasty habit of talking too quickly, and I do the exact same thing when I try to speak Thai. Makes it difficult for them to understand what I'm saying. Then again, when Thai's start talking quickly, I understand about 1 word in 10 (if that).
Phom kid wah khun phuut passa thai dee gwa phom.
Anyway, good luck with your plans. You'll have to let us know how you get on. I'd definitely be keen to hear.