Hello,
Welcome to HCM
As you are 48 year old pre-menopausal female,the symptoms you are experiencing are surely the symptoms of perimenopause.
As you have guessed it right,it is due to
hormonal imbalance particularly decreasing estrogen levels.
Sharp pain in the chest may be due to Gastrointestinal distress,
flatulence, gas pain or
indigestion that are common in this age group.
The feeling of impending doom and
lightheadedness are surely the symptoms of perimenopause.
So,do not worry.
I would recommend you to do following things.It will make you feel better:
1.Exercise
2.Maintain a healthy weight
3.Take enough calcium in your diet
4.Stop smoking if you smoke
5.Try going to sleep and waking up at the same time each day
Thank you.