NEED SOME ADVICE ON MY MIL!

Hi! I’m 19 and 34 weeks pregnant. My boyfriend is only 18 (he has one more year of school, I graduated) I spend a lot of time at his house, I basically live there and I love his whole family. It’s just him and his parents right now, their oldest moved out a while ago. Anyways, my friend asked me to babysit her daughter (my god daughter) for a few days. I obviously said yes because i always love babysitting her and it’s great “practice”. This time I asked to babysit at my boyfriends house so he could help. Oh by the way she is 5 months old. Well as soon as my friend dropped her off, my mil took her out of her car seat and walked away with her 🙃 every time she’d cry my mil would just grab her from me. She constantly asked to hold her, even if she just gave her to me! So I barely got anytime with the baby. I maybe spent a total of 5 hours with the baby out of the four days. AND she even made my boyfriend and I leave the house to buy her stuff and wouldn’t let us take the baby! I know this baby very well and every time I’d say “oh she’s crying because she’s hungry” my mil would refuse to feed her and say “no she needs to cuddle” or “no shes not supposed to eat that close together” And just let her freak for however long. And I’m really bad at saying shit but it really pissed me off. I felt like she was maybe over stepping? I get she wanted to help and she hasn’t had a baby in 18 years, but it was my responsibility to take care of the baby. I knew what I was doing also, I’ve raised two of my siblings, so I wasn’t clueless and I didn’t really need her to take over every time the baby fussed a little. It kinda worries me for when my baby comes.. especially since it’ll be just us two all day since she doesn’t work. I need to figure out my baby’s needs and make a routine. I just feel like I won’t be able to because mil will be constantly taking her from me. She keeps asking me to come over everyday with the baby. Asks to babysit even tho I’ve said I’m not comfortable having anyone babysit my newborn. I feel so overwhelmed. What should I do? Should I even be worried or am I being dramatic? and I’m not trying to be selfish with my baby at all!!