My push-ups had dropped from being consistently in the low 60’s to 53. Do you have any suggestions on how to increase them and keep a higher rep count maintained?

Consistency, diet, and sleep are the keys to that. Make sure you are doing at least 25 push-ups multiple times throughout the day and make sure you are giving yourself the adequate nutrition and recovery time you need in order to be ready. The other thing is that sometimes we just have a bad day, dont let it get to you too much.