7 month old not sleeping for me

To say, I try everything to get my little man to sleep for naps and bed. It is so heartbreaking for me. His grandma (my mil) holds him too much, which we’ve put a stop too, and she is the person he got comfortable going to sleep for. I have brought the situation up that it’s heartbreaking for me to my boyfriend, he says I’m being annoying and paranoid. He’s my first baby, and I’m feeling like I’ve failed. Any tips or advice would be a great help.

Edit: I’m a sahm, I am his primary caregiver. She told me today that she is trying to control his life because we are too young. We are 20 and 21.