Sleep regression and separation anxiety

My son is almost 7 months old and for a few weeks now things are been super tough. Getting him to sleep is such a chore, first it was at night. Nothing worked. He didn’t want to nurse to sleep anymore and had to be bounced or rocked for what seemed like hours each night to get him to sleep. And then he would wake at least 3 times. I would nurse each time and he would peacefully go back to sleep. Now nap time is so unbelievably stressful I don’t know what to do. He cannot self soothe no matter how many time we try. I bounce him to sleep, and attempt to lay him down and he’s instantly awake. Keep doing this for at least an hour each time and I get no where. He just screams and screams. He won’t nap. He’s so picky and I’m at my wits end. Is anyone else gone through this what else can I do!? Also, whenever I put him down or walk out of his site he just loses it. Help!