How do I get rid of bed bugs? Small infestation. Paranoid?

My grandma recently gave me her old bed. And few days ago, I woke up to bed bugs on my arms. Well, at least I know where the red spot/bumps are coming from. I thought they were an allergic reaction to something, lol.. The nights that I woken up with bed bugs on me, I freaked out and knocked them on the floor. My stepdad bombed my room, and sprayed in every small cracks in my room the other day. I scrub EVERYTHING in my room after. I washed all my clothes and got rid of my bed sheets and pillows. And if someone says I should vacuum the floor, I don't have carpet. My stepdad got rid of bed since he discovered most of the bugs there. I sleep on an air mattress now. But on that same day, that night I was laying down using my laptop and I saw one bed bug crawling on my laptop. Freaked out and dropped my laptop. I thought about killing the bed bug, but I lost it. I stayed up last night, hoping to find the bugs again, but I haven't seen none. So, I tried going to sleep, but I feel so paranoid. Like I feel itch all over my body, like the bugs are crawling all over me again. But when i look every where, there's no sign of the bugs. I hate this, I can't sleep. I don't know what happened to that one bed bug I saw crawling on my laptop. I feel like it's making babies in the walls or something. Help?