What should I do?

I think I might have to stop breastfeeding what do y'all think. When I breast feed my baby girl that is almost 4 months old. She acts weird like she isn't getting any milk anymore. Like she will suck and make noise the whole time like fussing and crying. I do know when I go a while with out feeding like at time like 5 to 6 hours and I go to feed her I can hear her swolling and that's about the only time I hear it. Do you think I will have to stop. I would hate to stop I was hoping to go until 1 year so this will be sad if I have to but I want my baby to be happy to be able to eat and get enough.