JUst eat a lot ..really..eat and do a lot of muscle training...make your self like a wall...i had the same problem and i watched LeBron James...he is so strong and he could only get crossed ...almost no one can run on him and get to the basket!!!
i bulked up from 61 kg to 75 in 4 months!!!my fat was 27% and it went off to 11%..so all is muscle excersize and eating a lot and eat right way!!