saddening

any mummies had to stop breast feeding because milk supply wasn't sufficient? i try to latch as much as i can so idk how much baby drinking but she usually latches until she sleep or spit out. when i do pump at night, i get about 100-140ml which is just nice for baby feed. she is 3mths n drinks 140-160ml of bm if bottle feed. I'm afriad I'll have to stop bf soon if my supply is not enough for bb. happened a few times bb will spit out nipple n cry, i try latch again she will suck awhilw then spit out. suspect not enough milk for her liao.. feel very sad n guilty if i cannot give bb bm