You've been doing this all your life. Everyone does it. Every time you make a decision that you implement into your life is a switch into another timeline path. It's called freedom of choice. Just know that there is a counter timeline where you decided not to do that. Our brains are wired to filter out the unwanted choice. Scientists have discovered a quantum reality where both outcomes for a decision actually exist. The entangled photon experiment is what I'm referring to. If you want to go to another timeline where the past history is different, consider making a decision that would be totally out of character for you. My favorite experiment was to change my daily habits. Try driving home from work by taking a different route. Put your clothes on from the perspective of someone with slovenly habits. Like getting more life out of dirty underwear by turning them inside out. Wear a shirt inside out. Maybe a different shoe on each foot. Kind of like trading places with an alternate you! And pay attention to changes in your immediate environment! I noticed that my key wouldn't open my front door anymore. The key teeth are always pointing upward when inserting key into lock. Except they now point downward. How about the color of your car? Is it different? Killing yourself is a major change you can't undo. Chances are you wake up in another timeline where your attempt failed. Or did it? You find out that you now have 3 kids instead of 2. Your spouse is a different person. You now have a brother!
I'm now entertaining a different explanation for my Doppelganger. I've shared my Doppelganger story several times on this forum. I suspected it was actually me from the future after inventing a time machine. But what if my Doppelganger is just me that chose an alternate choice to one I made. Other people can see the other me. But I can't! That would fit with the observed sightings.
Last week I recommended watching a new show called "Constellation". There are elements in this show that depict all of the above. And the writers of this series are very good at getting you emotionally attached.