Ghost? Negative energy? What should I do?

About 2 weeks ago I put up a cross in my room, That night I couldn't fall asleep, I would fall asleep for about 10 minutes, then feel very uncomfortable. I'd open my eyes and there would be this black blob in the corner of my room beside the cross. I didn't go to sleep that night. In the morning i took the cross down, & put it in my closet. That night the same thing happened. About a week after I felt like the blob was following me around the house, I was uncomfortable everywhere I went, You shouldn't be uncomfortable in your own house! That night I fell asleep for about an hour, I felt uncomfortable again, So I opened my eyes, The blob was beside my bed! I didnt flinch, I just stared at it. About a couple seconds of looking at it, It floated across my room into my closet. I broke down & told my mom. We searched up wicca, My mom said I have to smudge the house, By myself! I have to be the only person in the house. I put the cross outside, but everything got worse. While writing this i have to keep constanly looking back. What should i do?