A.,
I have a 4 month old baby and a 2 year old as well, so I know who hard it it to not get your sleep at night. Your baby Enza is gaining weight and healthy, right?
The best way to increase your milk supply is to NOT give your baby a bottle. When you nurse less often, then your body will slow down milk production. It sounds like your baby is going through a growth spurt and is hungier than normal, so you need to feed her more during the day... even if just for a bit.
You should make sure that you are getting enough nourishment in healthy foods and drink LOTS of water.
If you call your doctor's office, there should be a lactation consultant who can work with you on nursing.
Hang in there! You'll be adding rice cereal, veges and fruits soon too.
If I know my daughter has eaten well duing the day and she wakes up at night, I just give her a nuk to suck on and she'll fall back asleep until morning. You shouldn't have to nurse at night anymore! You need a good night's sleep!
Good luck!