I'm a little surprised you are running 5 days a week. I'm training for a half-marathon and the training plan I'm kinda-following (
Hal Higdon) only has me running 3-4 days per week, cross-training/strength training 2-3 days per week, and resting 1 day per week. I don't know how you would build endurance running 5 days--you get no recovery time.
I skate three days per week and run three days per week. To balance this, my schedule looks like this:
Monday - maintenance run
Tuesday - maintenance run & public skate
Wednesday - skating lesson
Thursday - public skate
Friday - long run
Saturday - off
Sunday - strength training or maintenance run
I'm not 100% happy with my schedule (I really hate my rink's schedule which forces me to skate three days in a row and have four days off), but it works well enough. For me, it's really important that I have a lot of recovery time after my long run day and that I don't run at all on my lesson days.
Are you fueling your added activity?
Not eating enough or the wrong stuff can leave you drained and instead of gaining you lose fitness and muscle.
Ditto this as well. And make sure you are stretching--I find running tightens my leg muscles and if I don't stretch every single day I have trouble with any skating move that requires leg flexibility.
Also, something I haven't tried that you may want to look into are ice baths. I know a lot of people swear by them to quicken recovery times after long runs, so if you need to run and skate on the same day and nothing else works, you could see if it helps you.