You are 29 and thinking about death and its aftermath. Please forget this, get on with your life. It's human nature to think about death, what will happen to our dependents ( parents, children, siblings), will they be looked after well, will they suffer in your abscence. Some individuals think of death and pray that they die peacefully. These are the common thoughts that goes into most people's mind in India.
In many western countries, some are obsessed with death and become misfits in the society, needing regular help. In some South American countries, people celebrate death as a festival to honour their elders who have departed.
Being constantly think about it necessarily does not mean suicidal tendencies but needs to be looked into.Are you deeply into violent games, video games that give points for the number of characters that you kill. Have you watched many movies that revolve around death, life after deaths, spirits etc. Have you lost a neighbour or a family member and were aware of what they went through the final stages.
I would suggest, please see a good psychiatrist and then move on with positive things in life. You have a long life to lead productively for people connected with you. Being positive, harbouring good thoughts, good feelings towards others, pick up a good sport or hobby and lead a life that's complete emotionally and spiritually.