>>I've been a day trader for five months but still can only made $2000~$4000 per months and I dont think I could do any better in the future.>>
Well, part of me wants to lambaste you for doing so well, so soon. But congratulations on your success! Given that you are already more successful than most traders, why not just continue to do what you are doing and make a modest living? Better yet, use some of that profit to increase your size, thereby increasing your profit and lifestyle? Your income would only be limited by scale.
I have no idea what your capital is like, but it takes most traders 1M to bring home $4k per month.
However, as other traders have replied, if you do not enjoy it, there are day jobs out there too. I refuse to work that way again, but I would equally hate doing something daily that I loathed, regardless of compensation.