Well, for one.. if you do believe in reincarnation, than get ready for a rude awakening (literally), because if you off yourself, that's a negative / you did not experience the full extent of your life, therefore your energy (soul) would be recycled and you'd end up with an even more shittier life than you have now. Maybe you'll be shoveling shit for the rest of your life in the next life afterwards or hell, a baby chick that gets eaten alive by a hawk immediately coming out of your bird mom's cunt (or egg - whatever).
The heaven vs. hell thing... not sure on this one, since suicide = hell apparently, but then again.. so does jerking off, so.. if we are to believe in the Abrahamic-system, then we're all going to hell no matter what. But, imo, we just die. We weren't here when Lincoln was in office, we weren't here when Bigfoot appeared on TV back in 1967 and we definitely weren't here when Rome fell apart, so... my logic is that we die, we disappear, we have no memory, because we have no conscious. I don't think it's a big deal tbh... people like to think heaven / hell is real because they'd like to believe people like Hitler, Ted Bundy and Vlad the Impaler are in hell right now, but for all they know... we all end up in the same place.. .in a ball of energy that just recycles itself.
Another theory I sorta have is kinda what Dragon Ball suggests when you die... you basically turn into a ball of energy and go thru some rehab / therapy type of shit, then eventually get recycled into a new body in a new planet, new species, etc. Idk... I'm just talking out of my ass.