That's a myth. Nobody knows who goes to hell. Can you imagine ever committing suicide? To me, a person who wants to end their lives is terribly mentally ill, out of their heads actually. I'm sure God takes that into account.
It's also not true that a suicide can't be buried in hallowed ground. Suicides need all the prayers we who are left behind can offer for them, so they are given the full Mass of Christian Burial, and interment wherever their family wishes.
You are correct. I lost a father-in-law to suicide and an ex-boyfriend (just last week) and have done reading on the subject.
From the Catechism:
2282 If suicide is committed with the intention of setting an example, especially to the young, it also takes on the gravity of scandal. Voluntary co-operation in suicide is contrary to the moral law.
Grave psychological disturbances, anguish, or grave fear of hardship, suffering, or torture can diminish the responsibility of the one committing suicide.
2283 We should not despair of the eternal salvation of persons who have taken their own lives. By ways known to him alone, God can provide the opportunity for salutary repentance. The Church prays for persons who have taken their own lives.