Have u tried to go to a public hospital and request that your baby be hospitalized? You'll be more relieved and less worried if the baby can stay in the hospital.
Similar to what happen my 20 month old son ah. He got fever 3 weeks ago ... 102F - 103F for 3 days, then get back to normal in the 4th day, and follow with rash (lot of red spot on his neck & back) ... that's Roseola ah! The doctor said always happen to 4 month - 4 year old kid.