Assumptions and Expectations

I know it's my fault for making assumptions and for creating expectations based on those assumptions.  I know I shouldn't get upset when it seems like those expectations won't get met.  But I do.  What else have I got?  Everything is so uncertain that I grasp at whatever seems most likely and try to create a viable future out of it.  It shouldn't come as a surprise when things falter but when they do, it unsettles me all over again.  Things are happening quickly, my life is about to change dramatically and I desperately need to know - for certain - what to prepare for.