Is there something you need to do to reduce her sensitivity? Seems that anything other than removing the blanket, nightgown, etc. results in a very large increase in awakeness - no idea how you'd creampie even once! she just wakes up
1) There is a sensitivity reduction upgrade in the skill tree.
2) There is a blindfold in the skill tree.
3) Upgrading your skill with relevant body part also helps.
4) Sleep potion in the potion shop. You have to buy it every time, and the price doesn't seem to match the price tag, but it reduces her sensitivity dramatically, and totally pays for itself.
Note that you can buy many upgrades multiple times.
But in the beginning, you just have to wait for her to calm down every time. You can even get your penis ready by masturbating, and then creampie her with the last trust (or three), waiting for her to calm down after every trust.