The best thing you can do is to constantly tell her how much you love her.
Hug her every chance you get.
You don't need to be a playmate for her to know she is loved.
I had terrible post pardum depression after my daughter was born tht lasted a yr I was really sick I even spent a few weeks in the hospital.... I never played with her or really talked with her everything was sooo terrible... now tht I am better I love playing with her... A few things I do with her even when I feel crappy are... I tell her I love her all the time and give her tons of hugs n kissies, snuggle with her on the couch while I'm on the laptop and she watches one of her favorite shows before bed I play the songs my girl and goodnight sweetheart and sing them to her... tht is her favorite... she is 2 now n honestly I think she will remember the small things like that before she remembers mommy playing leggos lol I totally understand where you are coming from... It gets better ... stay strong God Bless