No judgement please

When my daughter was born, I kind of got into my head knowing that she’s my last baby, I got out of the military and became a stay at home mom, and so In turn, I’m with her (and my 3 year old) all day. I didn’t realize it at the time but I hold her literally all day minus naps. I’m worried about her not getting enough tummy time. Her pediatrician isn’t worried about her but I am because my son was walking at 9ish months but she only scoots around on her belly. She doesn’t push up on all fours at all. She’s always hated TT and screams bloody murder when I put her down. I can’t even set her down in her high chair to get her baby food without her screaming the 30 seconds it takes me to get her food ready and a spoon. I’m looking for advice on how to adjust her to being put down for tummy time and also just so I can use the restroom while she’s in a seat or jumper without me in sight. I feel so neglectful when I put her down and just let her cry.