Hi, everyone, do someone know how to kill bedbug?

I live in a aparetment. My husband and I found bedbug about 2 weeks ago. I would say our mattress looks very new. I tried to use diatomaceous earth to kill bedbug. I would say it works, but not very effectively. I still get bite every day. I am so frustrating. I also use all kinds of spary to treat the bedbug, but they are still there. I search the many websites, but I still don't know how to do. I hope soemone can help me to solve the problem.