Great improvement, well done.
I've run 5km (4 to 7km actually and 10km once weekly) every day for the last year. The first thing I did was slow down and focus on running injury free. That's one of the big 4 ro 5 secrets of running everyday.
When I ran just 2 times a week, like you, I'd push more each time, and I suffered quite a few injuries. I've had none while running every day.
Cheers, good luck.