I am so tired my second trimester

Currently, I am 22 weeks. I feel so exhausted. I’m having trouble working and I’m oversleeping. I have iron in my prenatals but I don’t have any energy ever. I let my OB know today that I’m exhausted and it is affecting work but she said to just try to stand up walk around or do some squats to encourage a burst of energy. I just feel like the level of tiredness I have isn’t normal. I called out of work twice just to sleep. I’m taking naps during the work day and after work. I wake up for work and have to take a nap about a half hour in. I am just really struggling. My concentration is horrible too and I’m falling behind at work bc I have no motivation as I feel too tired to function. Any advice? Should I call the OB and stress how much this is affecting me?