Let me share something about what I've sort of noticed..

Alright, so let's just say for now that there is this amazing and powerful fire.. This fire is strong and vast as it engulfs an entire forest.. Now let's say that the fire dies down, and then starts once more after the forest is green and full of life..

The fire does not, under any circumstances, start at full strength. Otherwise it would take far less time to die down than it did previously..

This fact, whether you like it or not, is also true for spirituality. Just because you could do something before and an ability transferred from one life to the next, does NOT AT ALL mean that you will be able to use it as strong as you could in the past. It only means that your consciousness is used to the energy of that time, and as life and consciousness are forever changing, so are the vibrations of energy.

You have to get used to the energy of the world and teach your body to resist being harmed by this energy at the same time before you can use most abilities.. That's why a pyrokinetic or an electrokinetic don't accidently kill themselves when using their own abilities.. Please, just stop overestimating yourself because otherwise there will come a time when you want to use these abilities to your 'fullest potential' only to find out you overestimated and ended up physically hurting yourself.

I'm not saying that you can't ever learn to be that strong again, I'm saying that you have to crawl before you can walk no matter how fast you could run before you fell.