I can't help much, but I wanted to welcome you and to let you know that our girls are only 1 day apart in age.
My Myah was born on Dec. 2. You said your little girl was getting spayed next month? Isn't that kinda early??? I really don't know, but I can't imagine Myah getting spayed next month...she seems too young.
The only thing I can think of for your little boy is to keep him crated as much as possible and only let him run around after he has gone on the papers. Maybe he is like Myah, she won't go on the potty pads...she'll go if we take her outside.
I hope you figure it out before you go crazy!!!
