feel like a failure

so I posted a week or so ago how I finally went to the doctors and was diagnosed with pnd after 8 months of brushing it under the carpet. the pills I have been given are not working just yet but I just wanted to vent my anger and upset with myself. I love my baby to death and he is so so lovely but for the past week my mother in law ( who lives practically next door) has had my son every night for a week as I've just not just been coping very well and had quite a few side affects from the pills. so tonight I was geared up ready to have him back and after 4 hours I got major anxiety and basically had a melt down and he's gone back to the mother in laws for another night. I have him during the day just at night I seem to get this anxiesty. I'm so so upset that he's gone but I just wanted to write how sad I am because I love him so much but its like i cant control this feeling 😔