In the long run, be realistic about how many courses you can cope with per semester.
In the short run, since you are already overloaded; prioritize. Make a written list which includes every thing but ranked by importance. Allow an hour or more to make the list. Use the time needed to make the list as a time-out from the time pressure-cooker in order to clear your head. You really do need to break off from the panic cycle in order to work with fluidity.
Use your prioritized list as a flexible document which you can rearrange as needed.