baby not gaining weight!

my baby is a month old and shes still not back to her birth weight! she has only gained 2 ounces in 2 weeks!!! any tips on helping her gain weight?? I know shes not going hungry. she will sleep for 4-5 hours at a time. she doesn't always go that long between feedings but she will at times. if she was still hungry wouldn't she continue to want the boob and cry all the time?? she has AT LEAST 6 wet diapers a day but some days it's more than that. am I doing something wrong??? I'm a FTM. since my daughter has been born I dont really have time to eat a whole lot. I eat 1 solid meal a day and i might have some snacks here and there. usually the snacks are protein bars. I've been drinking a lot of water as well. I'm usually able to pump 2-3 ounces after feeding her. however i dont pump immediately after feeding her because she hates being set down when shes awake so usually i pump an hour after nursing. any tips would be helpful!! my doctor mentioned supplementing with formula but I'm really worried my daughter will start to prefer a bottle over me and idk when/if I'll be able to go back to just EBF.