How can I relax?

How can I relax and learn to become less stiff during training and sparring? People have commented on how I need to be more loose, especially with my shoulders. I would like my movement and punches to become loose, quick and fluid.

Can head movement drills help? Changing guards? Breathing exercises? I would say it's lack of sparring experience, but it's the same when I work the heavy bag and shadowbox. Nobody ever tells me how to correct this weakness. Thanks in advance for any advice.

Get God out of your corner ..... it's probably too crowded in there and your getting too much conflicting advice between rounds.

;D

Just calm down.
From your post it is obvious you think too much.

Sometimes boxing doesn't require thought as much as instinct.

Just be easy, don't tense any muscles and be open to factors beyond your control