If you have access to an acoustic,practice your barre chords on that.Practice the "E" form from the first fret,moving up fret by fret as high as you can go.Take your time and position your fingers so every note rings clearly.At first this will seem impossible and your hand and wrist will cramp-this is not a bad thing!!When you can take it no longer,extend your arm and flex your fingers back
towards you until it passes.Remember to keep your barre finger as close to the fret as possible especially near the nut.If you do this religiously every day,you will see your strength and endurance increase markedly.You will be amazed at how easily you can barre your electric after just a short time.Also get some books or web references to finger exercises and practice them RELIGIOUSLY every time you pick up the guitar before you do anything else.Do them until you
can't do anymore.This is one of the areas that makes or breaks guitarists.I have known many who aspired to play but gave up because they didn't want it bad enough to endure the labor.Good Luck