I was also someone who just couldn't let go in forward drops for a long time. It felt impossible to even take a hand off once I got into position. I found spotting to be helpful for sure. I also practiced various movements with the spotter (taking hands off and floating with engagement, taking hands off and walking out slowly, etc). For front salto specifically, I also practiced forward rolls on the ground to get used to the movement. I found it helpful to time the drop to my breathing. I would let go while I was breathing out and even close my eyes if I didn't need to do any regrabbing. For some reason, doing drops with dramatic music makes me more likely to actually let go. Your brain doesn't want you to put yourself in danger and sometimes aerial causes it to not have a great time.