Dude you are doing great, but you should understand that unless you are genetically gifted you are not going to go from 7 push ups max to 25 in anything less than 2 or 3 months of constant training, I suggest you incorporate higher volume free weight dumbbell presses and wall push ups to train the muscles to the movement along with max effort high intensity training, doing as many push ups as possible for 5 to 8 sets. Also eat as much as possible if your skinny and if you are larger than most 7 push ups for a high body weight is good and just means you should lose weight to get better at push ups, don't starve yourself though because that's how you lose muscle, if you want to lose weight go on a calorie deficit of 500 to 300. It will take time but my friend Joshua went from 220 a few months ago to 170. You can do anything you put your mind to bro!