My current fav is orange crush cordial (squash to you guys?) with about 10% fresh or bottled grapefruit juice added. Find a drink you like the taste of and try to move to that.
Read up on calf tears on here and do the right things. If you don't and you re-tear it by coming back too soon you will continue to have troubles. Been there, done that.
Don't know if these things are psychological or some minor ailment or what. I go through stages which might last a week or more of not being able to run up to my form. I try but feel lacking in energy and times are worse although I get back feeling shattered. Then all of a sudden I start running well again. Probably not much help, especially if it is something physical but hope you suddenly pick up again soon.