I invested half of my saving ($25,000) into ETH when it was $725. ETH has now plunged to $459. I am very worried I will keep losing money and I fear for the worst. I want to go kill myself 
You may not worried by losing money and fear the worst. The big thing you can do are hold and wait until the market price will recover.Be patience also and do not panic to sell if you're in losing a profit.