FEEDING AND SLEEPING ISSUES! CRISIS!

So my 4 1/2 month old won't eat very much in a day. When she's hungry she sucks for bit but then it seems like she forgets how to!? She sticks her tongue out lots when she feeds and then she stops. She only eats 6 times a day maybe at 6 oz. She always watches us eat and grabs at our food so I think she might be ready for solids.

Other issue is sleep. DD sleeps maybe 12 hours. She sleeps at 1, 2 or 3 am and wakes up around 12, 1 or 2 pm but it can sporadic. She doesn't nap for more than 45 mins throughout the whole day. When she shows signs of being tired, she screams and cries! We try everything and nothing calms herv down. How do I get her to sleep more? I can barely get anything done during the day because she doesn't nap.