Thank you for the responses. I just was not sure if this was just me, fibro, or something else. Aside from fibro, I have chronic low back pain. I had back surgery at age 37, almost 3 years ago. And now looks like arthritis in my joints. Yes, thank you DianaProser, I am on various medications and even pain medication doesn't stop that feeling. As PurpleStar stated, I can be doing nothing, having a good day... and bam, it hits.
Family, as SweetSufferingSandy mentioned, well it's very hard for them to understand that type of pain. Sometimes I received comfort and sometimes no one believed me (cared). So, I too, have silenced my pain.
It's honestly mind blowing how similar our stories are... PhyllisKingAllen I also experience the aftermath of pushing myself on days. I'm no good for days... And it starts over. Like a cycle you can't break.
Lupe1104 thank you for your response and I'm sorry we all have to deal with this. DianaProser thank you for the kind words.
I was able to show these responses to my husband so he would know it's just not me, and it's real. Sad, but true. Thanks again. Hugs and prayers to all of you.

iGreene, the fatigue just shows up unexpectedly and can stay for a while. It was my first indicator that something was wrong with my body 26 years ago. I could not get up with my baby. I had nothing left to get up off the sofa. I had to call my husband to come home from work to get the baby and me off the sofa. What a wild ride fibromyalgia has been.

Yes!
The exhaustion just finally takes us over! You are not alone!

yes I do ,. if I push & not rest -I will pay for it in the days that follow

Everyday! "It's all just part of the fun!" That's what I say when those closest to me ask me at least once a day when I grunt or grown because of the muscle pain and exhaustion as you described it! I try not to complain because I don't like to hear it from myself so I can't imagine what everyone else has to endure around me! "It's all just part of the fun!" 😬