My daughter is 8 months and she hasn't been feeling well, why?

My daughter has been waking up during the night for almost a week now, she hasn't done that since she was like 2 months old. She crys for a while, sometimes i've gave her a bottle to help get her back to sleep. She had a fever a couple nights ago, not again since. She had a rash on her back yesterday and it is gone now. I thought she may have been teething, but my neice went to the doctor yesterday and they said she has Fifth Disease, so I thought mine did to, but I looked it up and she hasn't had red cheeks, so Im not sure. She's pretty happy during the day, it's close to bedtime when she acts like she doesn't feel good. Also like a month ago I found a pea size bump on the back of her head, on the right side at the bottom. That has been scareing me , what could that be? She has also had more loose stools, like one or two a day, and she doesn't have a diaper rash, but after she has a loose stool, she's red in patcy's, like her stools are acidy. I hope you might have an idea of whats going on. She's been eating level Two foods for a month or so, and drinks 2-4 oz of juice a day, and she eats 28oz's of formula a day, if that makes any difference. Thank you. Becky