Infants are nasal breathers. So when nose is blocked, sleep disturbances happen.
You can use nasoclear drops even five to six times a day. Its just normal saline, so you will not have any problems. But if he has running nose too, it will add to the secretions.
If symptoms do not resolve, please do visit a pediatrician
who will prescribe some antihistamine and decongestant syrups.
Are you giving the formula in feeding bottle? If so he is more prone to get middle ear infection
too along with cold
. In that case child will cry lots out of pain. Breast milk is best for your baby. Since you have already chosen formula, try to give it with spoon in a propped up position, avoiding bottle.
Hope my answer helps you.