Fundamentally, you should load up your save and copy the variables out to work with them. You basically create all your variables the way you want then, with life etc, and when you want to save, you copy every single variable over to your save actor, and then save it.
So load the save from the slot. Get the save, cast to it, set your life on your player to the life from your cast save file. Same with location and everything else. The go through do what you want with the values you pulled from the save.
Then play. You life changes and location etc. So now you want to save, you make sure all the variables are set. Life is set, location vector is set, etc. Then you get your save actor, and set the life inside it. Set the location inside it. Everything. So that the save actor is up to date with all the relevant information. The you save the game to the slot.