Mother in Law being super critical since my baby was born - what can i do?

Hi ladies ❤️some advice would be much appreciated as this is causing me a lot of stress. I’m a first time mother and me and my fiancé have a beautiful 7 week old son,  I’ve never had any problems with my fiancé’s mum but since having our son she has been very critical towards me, it’s little things like when he was first born she had a pop about me dressing him in onesies all the time but I didn’t bother buying outfits in the newborn size I had all of his proper clothes 0-3 so when he would fit into them he wouldn’t be in a onesie all the time, I let that slide anyway. Now every time we go round for a visit she has something to say as soon as I walk through the door, she couldn’t see the car seat and thought I’d brought him round not in the chair whereas the car seat was in the car! Like I’d do something like that! Then she said his jumper was too tight and unbuttoned it, I know it could be me being over sensitive and hormonal but I feel like she’s always criticising me. When she came for a visit to our house with my partners dad I had my little man on his play mat whilst I was cleaning and as soon as she walked in she was like “as if he’s on the floor you should put him in his pram not on the floor!” And she said to my partners dad “look at him on the floor” so I just went upstairs for a shower and left my fiancé with them, couldn’t be doing with it. She also always phones my partner whilst he’s at work about things do with our son and always makes me feel not included. My partner works 40 hours a week and she hasn’t once bothered to come round and see me and little man, she just phones my partner saying she never sees our baby and wants us to take him round on my partners days off every week. When I’ve tried to talk to my partner it’s caused massive arguments, he had a go at me for not taking our baby round to his parents when he was at work, I’m willing to make the effort if they make the effort with me, it’s a lot harder to get out of the house with a newborn baby as you’ll all understand plus I feel like I’m being criticised every time I go round so it’s not very motivating. We almost split up when I told him how his mum made me feel because he defended her and said I was being sensitive and it was all me and it’s just the way she is. I don’t know how to deal with this because I know I’m hormonal but why should I have to put up with it? If someone has had a similar experience or have any advice please help😭