Bad feelings about my passed grandpa. Thoughts?

This must let you think seriously about afterlife

Never feed a negative energy with more negativity :) send out love and light and the negative energies will subside, that is my belief and it always makes me feel better.
Finding these things out about your grandad doesn't change what he was to you personally, the side you saw of him is the side that you know and should trust. I agree your grandad probably isn't sending you the negative energy, especially to scare or worry you but it is probably him feeling a little sad about how you perhaps perceive him after hearing this information.
Raise your energy and vibration, send out love and light and let your grandad know that you love and accept him and I'm almost certain things will improve.

xx

And yes always use protection, even when speaking to family.. once you are open you don't want to leave yourself open to any negative energies xx