Hi,
5th standard is really a very young age to make big decisions like marriage. In fact, I would say that second year of undergraduation is also an age that is important to make career and leave decisions for relationships for later age.
I can understand that having a heartbreak is difficult to deal with but committing
suicide and sacrificing your valuable life for a lady who didn't care for your love is not worth it. You must have your family and friends who love you and really care for you. They would feel cheated and heartbroken in the same way that you feel with that girl if you wont care for them and leave them by committing suicide. According to me, a life partner should be a person who loves you more than you love her and someone will surely come along your way if you wait. But to wait, you will have to live.
Move on with your life and do not care about relationships. Be progressive in your career. Make new friends and enjoy life with them. If you will waste these years, you will regret all your life.
In case nothing helps, you can visit a mental health professional and take
counselling sessions. He/she can also prescribe you medications to combat
depression till you are ready to move on with you life.
I hope this information helps you. Thank you for choosing HealthcareMagic. I wish you good luck for all the endeavors in your life.
Best,
Dr. Viraj Shah