Welcome to the forum. Thanks for your question.
Your statement "Reading online i am worried that i am exposed to hiv, hep b and other stds" suggests you have seen some inaccurate and perhaps non-professional information. I would rate this as a low risk exposure for any and all STDs, including HIV. Here are some threads -- with links to still others -- that discuss the STD/HIV of oral to genital transmission by fellatio.
http://www.medhelp.org/posts/show/1723730
http://www.medhelp.org/posts/show/1948289
In addition, it is statistically unlikely your partner has either HIV or hepatitis B. Probably she was immunized against Hep B, as are most people in Thailand; and HIV is now uncommon in Thai sex workers (very different than a couple of decades ago, but many websites have not caught up with Thailand's very successful HIV prevention campaigns for sex workers). And condom-protected vaginal sex is pretty much risk free.
Of course you can never go wrong with getting personal advice at a GUM clinic, and perhaps they would recommend testing for some STDs, mainly for reassurance purposes. However, if I somehow found myself in your circumstances, I would not be tested and would continue unprotected sex with my wife. If you are tested at all, the only things I wold recommend would be a urine test for gonorrhea and chlamydia and blood tests (after a few weeks have passed) for HIV and syphilis.
In the meantime, you shouldn't be worried. There is little likelihood you caught anything.
Best wishes-- HHH, MD