Danielle Fishelis opening up about the dreaded “mom guilt” she felt immediately after her sonAdler Lawrencewas born three months ago.

Adler — the actress’s first child with husbandJensen Karp— was born one month early and endured asubsequent three-week stay in the NICUafter doctors noticed fluid retained in his lungs. And while he’s healthy today, Fishel admits his entrance into the world kicked off the guilty feelings at once.

Danielle Fishel. Inset: Matt Winkelmeyer/Getty

Danielle Fishel baby

To add to her stress, Adler had a health condition called chylothorax — a “leak in the lymphatic system” that breast milk worsened. As a result, thecouple “had to take him off of breast milkand put him on a specially formulated formula that doesn’t use the lymphatic system,” the mom of one previously told PEOPLE.

RELATED VIDEO: Danielle Fishel Opens Up About Son Adler’s Health Crisis — and His 21-Day Stay in the NICU

In the three-and-a-half months since becoming a parent, Fishel has learned that “nothing in the world could have prepared me for the reality that being a mom would also mean never feeling like I’m good enough” — and that “none of us escape mom guilt.”

“It’s there whetheryou’re a stay-at-home mom orwork outside the house, but one there is one thing I know for certain each and every mother has in common: We are trying our absolute best 100 percent of the time,” she says.

One huge pro that has come out of Fishel and Karp’s parenting experience, though, is the fact that little Adler has already proven he can clear major hurdles in his life.

“I will always be able to tell him, ‘You’ve already done hard things,’ ” she tellsGMA’sKayna Whitworth. ” ‘You did one of thehardest things ever when you were first born, so no excuses. You can do hard things.’ “

source: people.com