Yes, it's okay if you weren't able to pray the novena because Jesus just asked us to go to confession and to attend Mass on Divine Mercy Sunday regarding the promise. That's what I read and have been told by others.
Yes, I had a wonderful Easter, thanks for asking! How was your Easter, my friend? I hope you are well. This coming Sunday is Divine Mercy Sunday. You've heard of the promise Jesus gave to St. Faustina, right? If we go to confession and Mass on the feast day of Divine Mercy then we are promised not only the forgiveness of all our sins but the remittance of all temporal punishment due to them. It's so excellent! Have a great day!