Thank you for sharing. That is an amazing story. Are you saying that you were injured when the buck jumped into your truck, and that is why you cannot walk?
I have read many books about reincarnation, and my conclusion is that it doesn't happen the way most people think. The hypothesis that makes the most sense to me is that the soul's energy integrates with a living person, who is in a position for the soul to continue the work it has begun. The human body is just a vehicle and sensory device. If you think of it as a bus for the soul, different souls in the soul braid can apparently take turns driving. Some say it is important to ask for the soul braid to be purified and request that any souls in your soul braid that are not working on behalf of 100% pure light and love be replaced.
If I were you, I'd meditate on the past life person who died in the car wreck and see if any memories surface regarding the circumstances that may have contributed to the untimely accident. Was there a trickster involved? Was there any unresolved regret, guilt, shame contributing to vulnerability? Did someone resent the person and wish her harm?
It sounds like she wasn't expecting to die so soon, which means she may have been broadsided by energy from someone who wished death upon her, in which case, you are most likely still experiencing the shock of it. To regain your ability to walk, you will need to understand how to protect yourself from such an energetic attack. If the person who experienced an untimely death needed to make amends to anyone, you could energetically do it. You seem like a very innocent and loving person. It may simply be a matter of learning to protect yourself from less benevolent souls, in possessoin of people who are not so innocent, those who intend to harm others out of fear, jealousy, rage, etc.