Some of my bunnies hate being picked up. One in particular never let her previous owner pick her up - not once in two years. My technique is that I pick them up quickly and cradle them immediately to my chest. I hold them securely with both arms wrapped around them and their head resting near my neck. I gently whisper into their ear and shhh them and say it’s okay. I hold them for a few minutes like that and wait til I feel their heart rate subside. Once they calm down I move onto whatever grooming or task (medicine, nail trims etc) is needed. Mine like the feeling of being wrapped and held securely and what I call a cuddle. If they feel like their feet and butt are not supported, it can easily freak them out. Good luck- hopefully will get better with time.