Hi Daniella,
There is a another website I really like, mediumystics.com
Everyone on this website helps people for free. There are also articles about mediums you can read about.
Definitely check the calendar, because they do different events every day and during their circles, I think they're called, they communicate with our loved ones that want to come through. If you keep joining into those circles they have, and if your grandfather wished to communicate with you, it's bound to happen.
Also I think our loved ones that have passed, we are still connected by thought, and anything you wish for him to know, he will know. I had similar situations with my grandmas, things left unsaid, and I asked them to come to me in dreams. Things were validated for me that way and it wasn't scary either.
Anyways, check that website and hope this helps you.