Help with 6mo. Old

I am a FTM to a 6 month old baby girl. It has been the hardest 6 months of my life. I have an amazing husband who is so helpful, family support and we are financially stable so i know life can be so much worse. I love my baby girl, so far she has no health problems- but she is SO FUSSY, like downright unhappy. She spits up constantly (today it was over 20 times) and will only play on her own for about 5 minutes on various bouncers, toys, etc. before screaming and crying. She will flat out meltdown for no reason. We are currently feeding her similac alimentum (which is the 5th formula we have tried) for those unfamiliar it is for babies with severe food allergies and colic symptoms, it's also crazy expensive. She did ok on it for like 3 days with a little spit up and mild fussiness but now she is back to even worse spitting up and fussiness. I am so exhausted, and so overwhelmed. The constant crying, laundry, carrying her around, is really tearing me down. Do you all have any suggestions? Words of wisdom? Anything would be appreciated. Thanks!