Financial aid/Scholorships for expat

My income is about $30,000 a year but when we add in my husbands income, out total family income is about $100,000. ($160,000 was a typo). I’m preparing to file now with the streamline program but it will cost me about $1,200 to do it. I’m gonna look into the Scottish universities and Scholorships. My son is doing the IB program and has good grades. Although he is interested in computer science, I’ve heard that the uk/Scottish universities as not very flexible once you have started if you want to change your major.