Eye heaviness & difficulty keeping open.

I have been having this problem for almost one year. I feel heaviness and tightness in my eyes with discomfort while opening them, as if my eyes don’t want to stay open. Earlier it used to happen mainly when I was sitting idle, but now it has started happening even while I am working or active. The episodes come randomly sometimes for 1-5 min in a day , sometimes it remains for hrs and then stop then again happen..most noticeable for me is after bathing in morning.. When I feel heaviness in my eyes and then forcefully keep my eyes open for a long time, I start feeling head heaviness and dizziness. I also feel excessive daytime sleepiness. There is no double vision. Eye check-up and CT scan were normal. My blood tests sugar, thyroid ,uric acid ,vitamins all are okay except for low d3 levels..Wind and cold water splash on my face gives some relief. The problem is not constant but keeps recurring somedays it's less somedays it keeps getting worse.