Hair thinning?

About two weeks ago, I washed my hair how I usually do, but a little bit more hair fell out than usually does. I didn't think anything of it, but when I got out my hair was drastically thinner and my usual hair type 3a was 2a. Since then, my hair has stayed at 2a and has continued to get thinner. It's not patches or anything like that- it's just not nearly as thick or curly as it used to be. There is no history of baldness in my family, and everyone has pretty thick and/or curly/wavy hair as well. the only thing I can think of that could possibly be causing it is that I started using new shampoo and conditioner. But that was a little over 2 months ago, and if it was the shampoo/conditioner causing it, wouldn't it be gradual, and not all at once? help i want my thick curly hair back :(