I know the feeling. The thing is, it doesn't feel like we are just losing a person that we care about, we feel that our inner core melts down and we feel worthless and expendable.
You have to realize that what you're thinking and feeling right now isn't the real you, but your disorder talking and twisting your experiences. You aren't worthless and you definitely aren't expendable.
The best you can do is to find as much support as you can from friends and relatives until the storm wears out. Only thing that really helps is time. You need to surround yourself with people who can make you feel that you are important and that this too will pass.
Who knows what awaits you on the other side. Keep writing here, don't let go.
Suicide is a permanent solution to temporary pain.