28 weeks and feel horrible

I'm 28 weeks now and my second trimester went well. Now I'm nausea everyday and so tired I can barely function. I'm light headed almost all day and just feel so run down. I can barely make it during the work day and just feel miserable. Sleeping isn't going well I wake up so much and cannot get comfortable. Anyone else feeling like this? I have my next appointment Monday but this is almost worse than the first trimester sickness :(