I Was Lifting And When I Was Trying To Get

I was lifting and when I was trying to get a last one in I was about halfway up when the weight stopped and I kept trying to get it up and that caused a lot of pressure on my head and afterwards I felt nauseous and I took Tuesday off and today I went back up there and felt good after warming up with lighter weight then I proceeded to increase weight and just a little bit of pressure on my head and I felt sick and like I was going to throw up and caused throbbing in my head. Almost like I'm hanging upside down