You're unlikely to be overwhelmed, at least by programming, at University.
I'm in my third year and the actual practical, assessed programming has contributed very little. Indeed, this year none of my modules have included any programming (although there was the option to).
Straight CS is a very varied degree, my modules have included everything from writing legal essays on Tort law to developing business plans for new ventures, from dissecting automata and studying complexity theory to designing interfaces for smart meters. There was also some Java programming in the first year!
My advice: Relax, dont worry about learning anything more than you have already. Going in with an open and clear mind is the best