Maybe someone else will have a practical way around this problem. All I can say is, in my opinion you are fully entitled to protect yourself from seeing your abuser. The right to protect yourself overrides any obligation you have to visit your grandmother in my opinion.

I agree with DW. Your health and wellbeing comes before anyone/anything else. It's understandable that you feel guilty, but your wellbeing comes before all else. To let your grandmother know that you're thinking of her, you could send her a card or have a family member that is going to her house for her birthday give her the card, that's way she won't feel like you're totally informing her birthday and still thinking of her.

I hate when we and our family have to pay because of someone else's evil actions. Im sorry you are in this situation and your grandmother is suffering. Were you living with her then when it happened. If you haven't sought counseling for yourself maybe it is time a good counselor can support you through the family situation. You are carrying to much of what he did time to give it back.

I just hate these scenarios. Chances are Grandma would love to see you too. Since he's looking after her, caregivers need breaks on occasion to get out and do things. Is there someone in the family that would be willing to give him a break? Then when he's gone, you can drop in to visit and leave before they come back. Just a thought...
Blaine

Thank you all. I appreciate everyone's advice. I was thinking this is God's humor to see how I will handle this. I've had my therapy. My therapist has given me the tools to self manage myself. I do/teach yoga that helps me to self soothe my anxiety.

I've felt for a while the that someday I will confront my uncle in a non violent manner. I thought maybe I would do it after my grandmother passes on someday. Maybe this is the time.

I have a deep concern, when people want to confront the abuser/s, especially men. I have talked a few guys out of this and know some who went to prison that did confront the person that abused them.
It's extremely rare that the abuser admits their wrongs, to say sorry. Extreme denial usually happens, then calling the victim a liar with very harsh language usually follows. Then the victim snaps and they suddenly find themselves in those shiny bracelets.
If you truly do want to do this, some guidelines.
Bring a friend, a very, Very stable friend. Tell them everything, you can then somewhat gauge their stability. Their sole purpose is to remove you from the situation if or when it starts to get hostile, dragging you away if necessary. You don't want a friend that's going to hold the prick so you beat on him better.
Record the conversation on your cell and if possible have a third person off in the distance video taping. Just in case the perp tries to press bogus charges against you. You don't want the person with you taping, they should only be focused on you and keep an eye on the perp also in case they attack. People knowing that down the line that they may be facing a stiff prison sentence will act out in desperation and even can become lethal, even family.
Do this in a public place, the perp may have weapons close by at home. Their less likely to respond with violence in public. At home a perp is more likely to "defend their castle himself" with violence.
Prepare for that denial so when/if it happens you're not as shocked or angered.
I probably missed something, but i'll also add that I've seen the calmest person, a person that I wouldn't have thought could snap, in fact do so, when the right buttons were pushed.
A part of me feels deep shame for talking those gentlemen out of their confrontations since to me it's almost like keeping the secret, silenced.Yet it just tears me apart when I hear of a survivor being revictimized when a confrontation goes bad and they end up in jail.
I wish you calmness and safety on this endeavour,
Blaine