you sound like a first time mother and are very upset as the baby is feeding all the time;but thats what babies are supposed to do,please do not supplement top milk;but try as i tell you
1.seep when the baby sleeps during day time as night time the baby needs you.
2.the sleep pattern of child will stabilize by end of 3rd month .
3.express your own milk during day time ,you can store and use it .
Next Steps
get your feeding technique checked,