Night Not Sleeping

My baby is 13 days old. She has been feeding on demand by FM, usually 2 to 3hrs for 90ml. However sometimes she ask for it even 1.5hrs for abt 40ml. At night she doesn't slp deeply, after milk will fuss and made alot noise till next feed. Is it gassy? I did try burp her, sometimes it works. I don't think I can keep feeding her but I am so tired from sleepless nights