Ghost? Negative energy? Help !?

About 2 weeks ago i put up a very old family cross in my bedroom, That night i could not sleep. I would close my eyes, But be very uncomfortable, When i opened my eyes, I would see a black figure of something in the corner of my room beside the cross, I would look away and look back and it would be gone. This has been going on for a very long time. About a week ago, It would start to feel like it followed me around the whole house, A couple days ago, I was sitting in my room, About to fall asleep, I closed my eyes for about 20 minutes, I began to feel really uncomfortable, I opened my eyes, The black figure was beside my bed, I didnt close my eyes or anything, I just sat there and watched it, About a couple seconds after standing beside me, It floated across my room & into the cross, Well thats what it looked like. My sister put the cross outside, I havent been having any trouble lately, But the house, (mostly my room) still felt uncomfortable, Me and my family searched up smudging, Me and my mom are going to a broom closet today, ( Wiqqa store ) to buy dried sage. Today my mom said i have to smudge the whole house, The thing that worries me is that i have to be the only person in the house. Help !?