My 7 yr old daughter

I'm so fed up. My baby is 7 and all last year from Oct-Mar she was constantly sick. She was sick then better couple days to a week later sick again. It was like I cud never keep my baby well for long. I took her to Drs and they said sinus infection, allergies, cold, strep throat repeatedly. I tested my apt at the time for mold. Then come Mar she got better and we were good to go. Well now it's starting again. Idk what to do anymore. Idk what is wrong with my baby. She woke up and she cannot talk n is crying bc she wants to go to school. And what's worse is if she misses too much school she drops a whole letter grade. I just need to know why my baby keeps getting sick. What's wrong with her. Drs just say same crap over and over. Getting frustrated. I owe so much in medical. 😢 gonna get a whole new panel of tests. I want her tested head to toe. Idk just need to vent. If any mommies have a idea what this is please help. She is mildly autistic diagnosed PDD. Not sure that has anything to do with it.