Having Dizzy Episodes, Feel Like Passing Out. Was Very Weak Couldn't Walk Or Talk. Recommendations?

I have had very bad dizzy episodes for the last month, and when they occur, I have to hold on to whatever is close by, or I will pass out. At one time a few months ago, I was very weak, couldn't hardly talk or walk, but I eventually got better. I am trying to be more active now that the weather is nice, and I do watch my diet very carefully. The dizzy spells are getting more frequent now, and I feel like I am going to pass out.