I remember those moments… still have them sometimes.

quick answer -
Can you leave the house for a bit? Take a break and rejuvenate with a friend?
If not, call another mother. Get out. Go to the park. Just be in the presence of another mom.
Spend some time thinking about where/when you can seize time for yourSelf. Think about the things you were/still are passionate about and how you might do something to nurture yourSelf on a regular basis.
Do something as simple as reading "mom quotes" to inspire yourself, laugh a bit.
Eat chocolate. But not too much.
Hang in there!!