That sounds fascinating!
Your interests are extremely important. We have to stay interested in our life. If not, we are trapped in feeling meaningless and depressed. That isn't a valid approach in my opinion. We have to analyze our interests, and use them to live our lives in a meaningful and fulfilling manner.
However, if you have an interest that is causing problems, we have to channel it in a better way. For example, a person might like playing music. That's great. If he starts violin lessons with an attractive female. that can be a problem. That doesn't mean it what he finds interesting is inherently bad, it's just not being properly focused. Even learning from a teacher that isn't fitting is frowned upon, while of course learning Torah is the greatest interest of all.
The interest in life and death, which in your case is being displayed as interest in near-death experiences, is I'd say a top philosophical issue of all time (I use philosophy loosely), maybe second to G-d. A thinking person looks around the world and sees amongst other basic truths that his or her time is limited. And longs to know what will be when it's over, what will happen then.
In fact, if not that we face an end and have faith in that there is an Olam Haba that has a din v'cheshbon, we would have all the excuses in the world to just follow our taavahs and whims. Especially as we get older, we see more and more that we have to chap-a-rine. I think Sefarim bring this as a reason that we do have limited lives, and as the Chazal say that we have to spend each day like it is our last. Also the Gemara that as a last resort, one should think of their day of death if in midst of potentially doing an aveirah. The idea of thinking what will happen when we die is not a problem, it's a question that Amoraim and Tannaim had.
So the question is not is your interest bad or negative. It's not. It's what's a good channel. I also don't think the idea of turning off our question side of our minds in matters of emunah is logical. We are a generation that wants answers, directions, not just turn off our urge to figure out what's what. Unfortunately, there is a limited amount of kosher options to analyze a lot of things online because we are just starting to use the interest l'toeles. There are shiurim etc.
Let me suggest the following matter that might interest you.
There is a sefer I got from a friend call Yalkut Meishiv Nefesh. It gathers divreichizuk from all over. The author is named Yosef Simcha Klien - his phone number in the sefer is (718) 871-8652 - with an Oak Park, MI address. I can't find online, other than a citing in a Jewish Press article. It's an amazing sefer on uplifting torah thoughts gathered from many sources to give chizuk to our generation.
On page 147, he discusses the concept of Gilgulim, and gives chizuk that a person could be living a life that is not the sole life per se of his life. And even if he feels that he has not succeeded or his life is lackluster, there could be other lives that are included and his end is NOT lack of success and an eternity of being pushed away. The author mentions in the note that this concept of Gilgulim is in fact recorded by the Chachamei Umos Ha'alom, mentioning a particular book in hebrew called Nishmas Chayim and in English "Children who remember previous lives - Ian Stevenson (Vivid Examples of Reincarnation in Recent Times). [I look and see on Amazon that he has a revised edition - this my own note not the sefer]. It says in the note that the Steipler quoted the book in his Sefer Chayei Olam many times.
Perhaps an interesting read to pique your interest that it seems will b'chazek your emunah not decrease.
Alternatively, speak to Rabbi or Mashpia for suggestions on sefarim that might exist on near-death aggadatas etc.