Baby not drinking well! Always fell asleep after two sucks!

I’m honestly going bonkers over my 3mo baby’s feeding. She suddenly became very difficult to feed. Taking longer to drink and doesn’t finish her milk. Milk will leak from her mouth while drinking…. I’ve changed multiple sizes of teats but none really worked! Made me confused also if it really was the teat issue… and she is always so sleepy during her feed. Suck every two times and stop… I’m worried cos i fear she is not going to have a proper weight gain at the rate that she is going. I dunno if its milk strike, and if it is, how do i overcome this? Any mummies have experiences like that? Can help this desperate mum here??#advicepls #pleasehelp