Just need to vent...

I've been exclusively breast feeding for the last 3 months, and recently I've been doubting my supply. Her weight gain has slowed down a lot, and if feels like she needs more... My mommy instincts are telling me she needs more but I wanted to breastfeed until at least 6 months but it doesn't look like that's going to happen... I love that breast feeding is just our time but if I give her a bottle then everyone will want to feed her, just feeling insecure about it...