So sorry for your loss, I just lost my Dad recently.
I personally think we have no real 'purpose', and that when we accept this, we begin to live life for today and that when tragedy strikes and we finally pass, whenever that may be, we dont die feeling unfulfilled.
Our legacy is the memories we leave behind and we know that in the minds of our loved ones, those most important to us, we will never be forgotten.
Take time to grieve, pain is natural and good. Be kind to yourself and the loved ones left behind, and cherish the happy memories.
My kindest regards and best wishes to you and your loved ones.