I once calculated the amount of antimatter it would take to get a good sized ship up to 50% light speed. It is a lot.
You need these speeds to avoid generation ships and it looks like the amount of energy needed for space travel is prohibitive.
Unless we modify our lifespans to last thousands of years I think that the stars will remain out of our reach.
It's a lot indeed, but we'll find a way, it's just a case of whether you and I will be alive when we do!
Cg