I have those (pretty much exact) intrusive thoughts all the time. If I went to hopsital every time I had them I would never get out of the place! They are just thoughts and as long as you can keep yourself away from the kitchen knife you should be ok. Just because you have these thoughts does not always mean you are suicidal. They are very scary and extremely annoying but they dont mean you are have to act on them.

I got advice from here to see the thoughts as an annoying child. That has been working for me lately. They pop up (all the time) and I just try to ignore them or tell them to go away like an annoying child. It doesnt always work but its better than nothing.