Note that the subject of suicide has already been discussed (What does the Bible say about suicide?), though not this question.
Suicide is usually an act of despair by someone with depression. There are remedies for the root causes behind suicide. Taking ones own life causes enormous pain and damage to those left behind, as well as the loss of the person himself/herself. It is not a loving act of someone who cares for others, and for this reason alone is wrong. It is wrong to take someone else’s life, and wrong to take one’s own life. To persist with any wrong thing knowing that it is wrong and to rely on God’s assumed forgiveness is quite simply wrong. It is no different to armed bank robbery. What is God’s response likely to be to someone robs a bank using a gun expecting to receive forgiveness? Obviously the bank robber was not sincere in any imagined repentance.
It would be extremely foolish to commit suicide knowing it to be wrong and expecting God’s forgiveness.
The best advice I can give is to seek help.