What Are The Side Effects Of Venlor?

I have been tired for the las two weeks , It feels as if I just want to put down my head and close my eyes. i am 53 years old and using venlor 75mg in the morning and venlor 37.5 mg in the evening for about 2 years now. I am also taking lamictin 50mg in the morning and evening for the same period. Why am I now all of a sudden so tired. My body feels ok but my head and eyes just want to lay down.