Workout routine for a year in which I can't fence

So I used to fence maybe 3 to 5 hours a week a year ago but since I graduated I didn't have time to fence much, and I got significantly worse in the past year ( going to top 2 of my club in a good day to like bottom 60% )

This year is going to be the same, so I won't be able to fence a lot but I would like to still get better trough the year to be able to compete again later,

I got around 15 to 30 minutes a day to workout, ( which i would like to do to be able to focus before studying )

During my last session I noticed :

I have really bad form ( specifically my guarde )

My endurance is shitty

My footwork is still correct but not the as good as it used to be

Does any of you have advices on how to setup a practice routine?