I Am Struggling With Finding The Word I Want To

I am struggling with finding the word I want to say. It's like my brain just freezes up. If it is a name of an object that I can't recall, I concentrate on the object in my mind and lately I've tried to 'see' the word I'm trying to say and just read it out loud. This started about 3 years ago and has steadily got worse. I'm afraid to speak in public because it's so embarrassing. At first I thought it was just hormones or something, but I've had 3 separate episodes today and need to find out more. Is this just normal aging? Where do I start?