Wow that's amazing you have really done Noble to your self @OgNasty also not allowing the pain you get through this push-up to discourage you not to continue is bravery that is why we that exercise always encourage ourselves with this particular speech NO PAIN NO GAIN.

The gain you get there is the healthy life style which you will enjoy after workout and during the period of workout.

Exercise is very essential just like you said that you feel much better these days thats one thing exercise does it make one feel relief after much exercise, exercise keeps the body strong and healthy which is most important health is wealth.