Unfortunately, I don't have time to develop my ideas for you sufficiently, so here's a little bit of an idea to get you started, if you find it helpful.
Your first verse at present says:
See this backpack has some good and bad feelings
They are just weighing me down
So heavy this baggage
Drooping down my shoulders like a sorry frown
But take off one strap and i feel the release
I don't want these rocks on my back
All i want is peace….
You can broaden the feel of this by just changing the first line...maybe something like:
I am always loaded down with strong emotions
The weight is just dragging me down
That still needs more work, as having the word "down" in both lines is too repetitive, but it's one idea for being less specific.
Good luck with this. I hope to see updates soon.
Vicki