Aaaww you remind me of myself back when I was 18. Writing and listening were easy , but I had an issue with speaking. I was too afraid the other person would have a hard time understanding me, so I was speaking so softly and often tried to translate from Indonesian to English in my mind before I said anything. WRONG - the key is NOT to translate what you want to say. Through time I learned to start thinking in English, and 'magically' my sentences became a lot more fluid. At this point I started speaking with more confident, shortly after, my friends and colleagues often forgot I was an International Student because I had lost my accent completely
Edit : I just read your comment about how people would call you 'sok bule', YEEEPPPPPPP that happened to me too lol
but hey, look where I am now and look where they are! Incase you ask, 'where are you now, anyways?' - well I'm a 29 y/o Indonesian female with a successful career in Finance, well on my way to six figures salary and living in Paradise (Cayman Islands in the Caribbean). Which happens to be one of the top world's financial centers. I'm not bragging or patting myself in the back, really and truly being able to speak english properly has opened so many doors for me. And it will do the same for you - it will bring you places, the world will be your oyster. I am a living example of it. So to those who made fun of me in Jakarta - I'd say, 'Eat my dust, Muth*f**ka'!' ROFL and if you keep up the effort, you will be saying the same thing to those people!
Take it from me - don't be discouraged!