I feel terrible and guilty

I'm 11weeks & 4 days and have been in bed the whole day due to tiredness, headaches and nausea. I've only been up to empty the dishwasher,make my husband lunch, make some hot lemon tea for myself and of course to go to the toilet a thousand times!

Yesterday I had a good day- I was able to do housework, a bit of paper work and even go for a walk but today is complete opposite. I feel like such a failure that I haven't done anything all day and the guilt is high. My husband is out working and I'm just in bed 😔.

Does anyone else have days like this?

Is it ok for me to have a day like this or am I being selfish?