I have noticed for years that i feel okay in the mornings, butaround noon, i start feeling weak and exhausted. this getsbetter around 4 p.m. what should i do?

Many possibilities: When do you take metoprol? If in am, could be cause. Do you have morning coffee? Morning carbohydrates? Obligatory intervals of fatigue happen with these typical intakes. Could also be related to sleep variant, morning exercise (or lack thereof).

Diet may be the 1st: Place to look. Fatigue at the same time suggests lack of water, or glucose especially around times of peak metabolism. Consider eating 30 grams of protein in the morning, drinking plenty of water and then see how you feel around lunchtime.

Weakness: Do you get enough rest at night to last you through the day? Also, do you get to eat through the day enough to maintain adequate sugar level in your system? What do you normally do around this time of day? These questions need to be answered to further tap in your case.