Whenever an asana works on stretching body parts it’s good advice to have patience. It takes time to stretch. Being overambitious causes injuries. Injuries are setbacks. Sometimes indicating an asana might be enough. It’s better to establish again a daily yoga routine than to force the body into a position that is too demanding. Especially after a break one must take it easy. It is disappointing to lose asanas. As in life there are ups and downs.
Knowing when to give 90 % and when not is something we learn over time. I wrote 90 % because we cannot give every day 100 %. I even read that sports people get to better results when they take it easy.
To hold an asana longer than only 5 breaths will help to advance relatively fast.
What is worth doing, is worth doing daily.
To practice daily is so much better, than to have long and intensive practices once in a while. This might sound banal, but it’s true.