Heh, I relate to this a lot. Went for CS a decade ago and bombed out because I couldn't grok calculous. Now I'm working as a systems administrator and making 6 figures a year at an MSP. One thing I will absolutely recommend is if you go into IT, is to make sure you know how to use native platform scripting (bash/powershell) and work on keeping up with it as well. It will open all sorts of doors for you.
Knowing powershell as well as I do 1) is a decent part of how I got the job (pitched myself as being able to automate parts of their build processes) and 2) quickly made me indispensable for my team and within a year of starting I was already promoted to a senior administrator.
minnieo