HI Littletune!
Above all a prosperous and happy new year to you and your family!!May I just say that for a teenager you are so deep into thought about questions of life and existence and your manner of expressing your thoughts and ideas is so profound and uncommon for your age. For me it is good as we will have one human being less attached to all the inanities of the world!
I have always believed that there are innumerable questions that at the moment and for a time to come cannot be explained by science and can only be believed through faith. One of those is the afterlife. For me, man's knowledge of things or his logic and understanding has yet to evolve to a level which can elucidate such questions. I also believe that our present scientific devices or tools are still crude and rudimentary when used to answer such questions. And maybe the proof to such can not be achieved if we view and seek answers through our usual ways of perceiving and documenting in our physical world.
Something happened in my younger days that has greatly influenced the way I look at these questions and please bear the length of this story. This was in the late 70's when I was a medical clerk ( a 4th year medical student). One of the senior medical resident, age about 30, "died" due to complication of a severe viral infection to his heart. All the top doctors of our hospital were in frenzy trying to revive and keep him alive. He practically had zero blood pressure and no spontaneous respirations. He was in deep coma and only machines like the ventilator kept his breathing going.
I was the most junior of the team on duty that day ... so I was 24 hours on bed-side duty. There was also a medical resident exclusively assigned to watch over him. You can say it was super VIP treatment since he was one of us. Normally it will be the nurses keeping watch.
After several days he regained consciousness and eventually his blood pressure stabilized and no longer required supporting medications and he was taken off the respirator. Since I was still assigned to him, he told me stories about his "out of body experience" and the usual dark tunnel into the bright and overwhelming light thing, a common experience among those near death. Frankly I took those stories for granted and dismissed it as the effect of his reading too many books about those.
However he told me some things which shook me and up to this day I can not just forget. In his "out of body experience" he went down or floated to the hospital lobby which was 4 floors below and saw this hospital employee talking to a young attractive woman. He identified the employee and described in detail the woman. He even gave the date, which was the 2nd day of his coma and the time it occurred. He also floated to the medical residents living quarters which was in a different building and saw a few resident doctors taking a rest. He also saw a resident doctor cooking his meal in the kitchen. He was able to name all the doctors, there were only 5 then, what they were wearing and doing, some sleeping, some in shorts (even the color of their shorts), all shirtless and what the other doctor was cooking. On the way up back to his room he entered an empty hospital room and saw this doctor using the toilet of that private room (hehhee).

I was able to verify all the events to be true to every detail and this has bothered me with so many questions up to today. How could he have known correctly such details as he was in coma and attached to respirator???

"Logic" tells me that the only way for him to have seen and witnessed the events he described vividly was to be really out of his physical body in some form since at that time he was in coma. In that same light ..... then there must have been also a form of "consciousness" and "reality" when he experienced the dark tunnel or blackness into the bright light thing. At that moment he felt extremely happy, an indescribable joy enveloped him but was asked by an elderly man to go back as people still needed him.
You can say that our subject doctor was a "playboy" as he had 2-3 girl friends at the same time and he enjoyed the night life and gambling. By his habits he definitely was not a religious person. He sort of lived for the day as if the end of the world was coming soon. He was back at work after 10 weeks, but he was a totally changed man. After residency, he entered the priesthood and now is the director of theology of their priestly order. Whenever I meet him, he would kid me that he pitied me a lot because he saw in my face that I am grappling and doubting my faith about God's existence. ... and with a big grin and a wink of his eye he would tell me in a loud voice "I have been there and I know that it is true, there is a God and life after death".