Our final destination, heaven or hell, is based only on a person's relationship with Jesus Christ. Being a "good" person has nothing to do with it because the standard is perfection and none of us can obtain that here on earth. We are saved by the foreign righteousness of Christ earned at the Cross and given freely to those who ask. All others are damned no matter what they do.

We are all going to die someday in a manner known only to God. I don't believe that suicide, in and of itself, can necessarily be considered a mortal sin. There are many factors to be considered and those are known only to God. We must trust Him to make the right decision in these situations.