Once you get into the swing of things, it should be doable for you. Try not to look at the whole picture at once - once you’ve found the middle of the Aida and the middle of the diagram, just focus on an inch square of the diagram at any one time. One tip that I don’t do but know it helps a lot of people is to mark each stitch on the diagram, once you’ve stitched it, in yellow highlighter pens. That way you know what you’ve already done