That's pretty poor on the hospitals part, I hope they've arranged you some follow up ASAP to help you. I assume you're Type 1, so you should have been prescribed a long acting (basal) insulin which you take once a day, as well as your Novorapid, which you take to deal with the food you eat. If you look at your discharge letter from the hospital does it give any dose recommendations on that, or any clue about how soon you will be followed up? Definitely call 111, they should be able to get someone to call you. I hope you get some advice soon.