Can normal but gassy baby drink Nan HA?

My baby is 6 weeks old and my bm yield is low so I decided to mix in formula as a top up for night time. He is very gassy and spit milk/vomit almost every meal. Every meal he will want to pass motion and will gek sai till milk come out even from his nose. After drinking and burping, he will still vomit a bit of milk even after resting before lying him down. So far he poops a lot a day and everytime during or after feeding. Didnt see dr for any diagnosis and not sure if I should give him Nan HA as I bought this instead of Nan. TIA