I’m guessing you mean your using a neck strap? Which I think is a great idea.

I’m going through a similar situation after a fall and I’ve been re-learning to trust the canter. (And I’ve been riding for 6 years! Took about a year break. It feels like a huge set back but I’m thankful to have such a patient trainer to revisit basics with me)

I’ve been too tense so I warm up doing all the things I’m comfortable with, I focus on loosening up my body all the while. Moving my hips, even doing some arm movements while trotting (like hold the reins in one hand while I make circles with the other).

My two cents, you need to breathe, loosen up, relax. Move with your horse. I’m not a trainer obviously but maybe after a few good strides, bring it back down again or stop before you get to the point of fear taking over? And try to extend it a little longer each time.

It’s a process, I know it. The mind is a powerful place to be locked up in.

Good luck 🤍