On question 2, the number is not the problem, and this is where most advice goes wrong by telling you to do 60.
At 40 reps you are training muscular endurance, not strength or size. Those adaptations come mostly from sets that are hard within roughly 5-15 reps, taken close to failure. Adding reps pushes you further into endurance territory, so 60 a day gets you better at doing 60 a day and not much else. That is a fine goal if it is your goal. It does not sound like it is.
The honest framing: you have been doing cardio for your chest for eight months. It is not wasted, you can do 40 push-ups, which most people cannot: but it is not the thing you were expecting it to produce.