Positive Vibes,
I wonder if you are getting good sleep. Caring for an infant challenges the sleep process.

You may also be struggling with hormone regulation.

I would encourage you to get assessed by a Women's Health specialist who is an expert with bio-identical hormones. Your brain is likely more sensitive to hormones that most women.

No, you are not losing your mind. Your mind is under stress and struggling temporarily.

btw, Many of us believe PCP/GPs, OB, and GYNs should not be prescribing psychotropic meds. Few have the proper training in psychotropic meds.