I Am 62 Years Old, 5'3", And Weigh 125 Lbs.

I am 62 years old, 5'3", and weigh 125 lbs. Recently, many evenings when I have dinner, I have a burp or two and then I feel like I am going to pass out. I hang onto the table so I don't faint.I can't talk very well, and everything starts going black. But then I come back. I actually passed out 3 years ago, went to the hospital, had all kinds of tests run, and no diagnosis. Could this be a potential stroke situation?