I would suggest taking it slow. Does your course allow you a bit of time where you can still drop a class without penalty? If so, I would suggest trying it for that period and see if you can cope with the workload.

And just take it as slow as you can. I often end up more panicked at certain times of the year so make sure at the beginning of each semester that I get my diary and work out my study load each week (setting regular breaks) so that even when I am not doing so well my study doesn't suffer too much. It also helps me to not get too far behind.