It sounds like tetralogy of fallot to me. Of course I am not a medical doctor, however, my daughter was born with this condition.
Your child will require open-heart surgery to repair his/her defects at some point.
It does indeed sound like your child could have a complex congenital heart anomally called Tetralogy of Fallot (TOF). In this condition, there is a large hole in the wall between the lower heart chambers (VSD) with aortic override and varying degrees of blockage of blood flow to the lungs (pulmonary stenosis= ps). When the blockage is severe, it limits the amount of blood flow going to the lungs and causes blueness of the lips, tongue and extremities (cyanosis). The low oxygen level can impact upon the child's ability to grow and develop. In fact, if the oxygen level is extremely low, the child could die of what is termed a "spell" where the oxygen level goes low and acid builds up in the tissues. TOF is not something that gets better by itself, and long term survival can only happen if open heart surgery is performed: a patch is used to close the VSD and the surgeon creates a pathway for blood flow from the right sided pumping chamber to go to the lungs. In western countries, this surgery is usually done within the first 6-12 months of life, or sooner, if symptoms warrant. The degree of blueness /cyanosis is key in that decision making. Your child needs to be seen soon by a pediatric cardiologist and congenital heart surgeon. It is important to understand the severity of your son's particular TOF situation (they are variable in severity) to determine the timing of heart surgery.