Hello @marymaynacu and welcome to Mayo Clinic Connect! As @erikas mentioned in her earlier post, we are not medically trained and can't provide diagnoses or treatment but we can share our experiences with you.
First of all, you need to see your doctor. You do not mention if you have other problems with your throat such as post-nasal drip or other speech difficulties. Do you have any other health problems that might be contributing to your weak voice? I'm thinking of heart, lung, or neurological problems like MS, Parkinson's, etc.
If this problem persists your doctor may refer you to an ENT specialist who can look at your vocal cords and determine what the problem might be.