Whether or not one gains entry to heaven after suicide is dependant upon several criteria:
1) Unless a person was actually in faith in Christ at the time of his demise, he would NOT gain entrance to heaven. Simply put: if an unbeliever dies by his own hand, he will not see heaven because he is an unbeliever….NOT because he committed suicide.
2)If a ‘believer’ in Christ commits suicide, it is the motive for the suicide that would determine his eternal outcome.
For example, if the believer committed suicide based upon a premeditated and conscience motive to harm himself OR leave others in guilt or shame or perpetual remorse, OR to escape legal punishment, OR out of cowardice, OR in determined sin, OR out of total rejection of the Faith…there would be no heaven for this individual.
Judas Iscariot is one who would fall into this catagory.
On the other hand, if a believing person suicided himself by accident, as the result of mental illness by which at the moment he had no clear knowledge and understanding and intent to do evil….such a person would likley gain heaven as an innocent.
Put short: God never condemned anyone who by accident or illness hurt or harmed themself.