Why am I most tired in the mornings?

I’m exclusively breastfeeding my 3.5 month old, who is still up 2-3 times each night (+ often an early start). I feel pretty good waking up during the nights, but the morning...ouch. I don’t know why it’s so different. The days are then often getting off to a bad start, and needing my husband’s help with the early starts is causing tension in my marriage.

Is this just normal? Any suggestions to help with being more awake in the mornings?