uoti

I'm in my final year of a three year BSc in physics from Imperial College and I'm really keen to study computer science, computer engineering, any kind of tech subject really, in the US. This year I already tried applying to four schools: Georgia tech, Cornell, Brown and UCSD, all for subjects of this type. However I got turned down from Brown and haven't heard anything from the others, and it's been over 2 months since I applied. I believe it's unlikely I'll get offers from any of them. Whilst my grades are OK, (average 68, so GPA of ~3.6) I have very little knowledge of computer science and little programming experience because of my physics background. I have used python and am familiar with object oriented programming but that's about it. The only internship I've done was in physics research with little technical exposure. The academics I go to for references are physicists and only know about my ability concerned with physics. I'd like to try applying again, this time to more schools. But how can I make my application more convincing with so little experience in computer science? (Honestly I'm really more interested in computational methods within science and engineering, but find it hard to find courses like this). I want to get a 6 month or year long internship in this field to make me more convincing, but again landing an internship like this is hard for a physics student. Sorry this is so long. I'd really appreciate any advice, no professor I know is really familiar with this and I feel like there isn't much guidance out there. I think I made a mistake applying to courses I clearly didn't have a chance with and I really don't want to make that mistake again. Please help!