Grief is expressed in many ways; sometimes in ways that are hard to understand. It sounds to me like your parents are having a very tough time dealing with the loss of their son and are terrified that they may lose you too. It’s not that they want to crowd you or make your life miserable. They can’t see that their insistence on being so involved with your life is hurtful. On what may well be an unconsious level, they are being protective and making sure that they will be there to help if anything bad happens to your family.
I know it feels like they are guilt tripping you but I think what’s going on can be better understood as their feelings of guilt and regret that they didn’t spend more time with your brother or weren’t there to prevent his death. None of this is rational, of course. This is grief that is unresolved. It therefore won’t do any good to be angry with them or to try to reason them out of their feelings.
Instead, it might be helpful to talk sympathetically about their feelings and to remind them that your life as an adult still has to go forward without their constant presence and protection. You might remind them that there was probably little they could have done to prevent the loss of your brother, their son. Whatever their good intentions, intruding too much in the life of your family won’t compensate for whatever regrets they have about how they related to him. Your conversation should focus on how to get back to something more normal. Your brother would probably want you all to have a healthy, positive relationship with each other that includes fun, not frustration.
If you can’t make any headway, you might suggest that you all see a family therapist together to work through the grief. There’s a hole in your family that was left by your brother. Your folks need help coming to terms with the fact that extra time with you won’t fill it. You need some help in establishing a reasonable role in your parents’ lives. Two years may seem like a long time but it’s not unusual for it to take up to five years for people to work through a significant death. I hope you and your parents can find ways to honor the loss of your brother that will also allow room for life to go on.
I wish you all well.