Does anyone have tips for letting go and being more confident during sex?

I used to feel more confident when i was younger with perky boobs lol. I still think i look hot but my boobs sag now after having a baby. My boyfriend doesnt care tho and he loves me and my body. Also i feel like im making weird faces. When i let go ive had the best sex with my boyfriend where we feel super connected. But most of the time im overthinking the entire time and i find it hard to let go. I havent had that mind blowing sex lately and i know its because i cant let go. I trust him and everything. Im also confident in my sex skills lol. But how can i truly let go and be in the moment??

And i dont want to use alcohol to get there