MitchiestInge, I can see why you are confused. You get admitted to hospital, someone is very nice to you, then they contact you.
Regardless of how 'nice' this guy is, he has broken fundamental rules, and has illegally used your contact details.
You'd be amazed the power a care assistant/nursing assistant/health care worker/whatever's uniform alone has. Before I did my Nursing qualification, I worked on a ward in a hospital.
I could do anything. I went in to a cubicle, to remove a cannula from an older gentleman, to find him naked, having a strip wash. As I apologised, he said 'It's OK dear, you're a nurse.' That was the day I truly understood the power that was entrusted to us. That man, fully aware and with all his faculties, surrendered his decency to a 20 year old girl, because she was a 'nurse'.
There is no way that this guy didn't realise you were vulnerable. No way at all. Every shift, there is a handover, and all care staff are updated on the needs and welfare of all patients on the ward. If you were saying the things you are reporting, you can bet your bottom dollar that some small comment would have been made about your state of health.
I also agree with other posters, who say that the next person may not have a forum of people to ask. This is behaviour which needs to be stopped. Please do take the right action.