It's okay to grieve the life you were "supposed" to have, feel that pain, let it flow through you like a river.
Thinking of it like water helps, water needs to keep moving to keep from becoming stagnant and toxic.
If you don't release your feelings, they'll stagnate and turn into bitterness and regret.
Try different things until you find what works for you, meditation, journaling, yoga, anything that keeps you flowing.