I’m sure there are plenty of similar discussions out already, but just felt like starting a new one… 
I just wanted to share how much Eckhart Tolle and his teachings have helped me. He’s a renowned spiritual teacher who’s focused on spreading the message of the power of now (that’s also the name of his first and most popular book). He teaches the power of presence and the debilitating effects of too much thinking. Pain is inevitable, suffering is optional. And it’s our thoughts that create suffering. Whereas if we allow pain to simply be, it dissolves. He also talks about suffering being a portal for awakening and becoming a better human. Our true essence is indestructible, our form, aka our bodies are subject to life and death, but our true essence is immortal.
Now, his work is not focused on grieving per se, although he does touch the subject briefly here and there. He teaches a new way of being, which essentially helps in all aspects of life, including when it comes to grief.
I came across his work about 3 years ago and it has changed me profoundly. It takes time to grasp his message (I probably still haven’t fully, still learn new things every time I reread his books or watch his videos), but is so worth it. I strongly believe I would have been in a far worse place right now without his wisdom.
Excuse the long post, but I hope some of you may benefit from it 
His books are widely available. I’ve read The Power of Now and A New Earth. They’re both amazing.
There are plenty of his talks available to watch on YouTube
Thank you for reading my post