I am ridiculously tired this

I am ridiculously tired this morning. I went to bed shortly after 10pm last night, then sat reading until around 11pm. Lights out. Cue restless fidgeting until 12.30am. I gave up, turned on the light, and started reading again. Eventually, around 1am, I felt ready for sleep. And then I woke up around 2.15, 3.30. 4.30 and 5.45. Why? I even had a hearty glass of red before retiring, which usually helps me sleep.