Merging Timelines to Create a Shift
When you perceive and choose to shift to an alternate timeline, you adopt the past, present and future of your new timeline. This is why it is not necessary to go back in time to change the past. You are able within your present moment to merge your current timeline with an alternate timeline.
An example might be that you develop a condition in your body that is a result of past choices. You may feel this condition is irreversible and others may tell you this as well. At this point, you may feel hopeless and wish you could travel back in time to convince your past self not to make the decisions that activated timelines where you are experiencing serious illness.
You would do just as well to begin perceiving the timeline where you are healed and whole and begin merging with it. When you begin tuning into the healed and whole timeline, you naturally adopt the thoughts, feelings and vibrational frequency of that timeline. This allows you to tune into and merge with the healed and whole (or any other) timeline that already exists within the hologram of your present lifetime.
For more on timelines, see Timeline and Identity Shifts: the New Science of Reality Creation by DL Zeta