Sexual harassment at work

I've never thought that I would ever be harassed... Not that it happened for many times.

The first time was a week for I return to KL for summer holiday this year, worked at a psychiatric ward. This elderly male patient, A, kept smiling at me, and wouldn't it be rude if I just look away? I smiled back every time. And then over one or two hours his smile went funny, more friendly. Later on while I was standing nearby, he suddenly walked towards me and hugged me very tightly and kissed my cheek. Before I could react, another male staff noticed and saved me. Did you know what the staff said to A? "That was very bad you naugthy man." Anyway it didn't mind eventhough the permanent staff insisted that I fill in an incident reporting form.

The next one was a patient that I've met twice after my summer holiday. He suffered from alcoholic liver disease, I suspect with encephalopathy. The first time I met him, he was really agitated, half the time trying to climb out of bed. From breakfast through to lunchtime, he was asking me to have sex with him, with him holding his penis and being naked, crying 'come on, lets get on with it' - o dear - and I was alone with him in a side room doing one-to-one care. But I knew he was not capable of doing any harm as being sick he didn't have the strength. The next time I worked on the ward it was three or four weeks on. He wasn't as confused but I also noticed that he's lost a huge muscle bulk on his legs, which was really sad - but who wouldn't be after being forced to stay in bed for three weeks continuously? Yet the sexual disinhibition was still there in that he still refused to get dressed, kept holding his penis and asking me to have sex with him. Strictly speaking, this doesn't really count as sexual harassment since he was clearly confused, yet he did leave me frightened for a moment.

And today, about patient C, it was almost certainly outright harassment. The ward was really short of staff and I was rushing around like a headless chicken trying finishing my morning washing. So I was quite clumsy, knocking over things, spilling drinks and kept apologizing to patients.
When I went to patient C behind the curtains to help him have a wash, he said 'stop apologizing, you've done nothing wrong'. That was nice of him, I thought. 'OK,' I said.
'Tell me what have you completed today?'. Trying to boast my self confidence? No need for that - no time to waste. 'Not much,' I replied.
'Don't understand what you mean,' he said. And then he started putting his hands around my waist and then rubbing it down my bum. I walked away out of his reach right away. Then got back to business, getting him to sit up and have a wash.
I know I should have been stern in telling him off. But I just can't do that. I can do a lot of things but telling people off and rejecting people are not my strong points. I could have told one of the staff there but I was occupied to the last minute before I finish my shift. So I'll just let it go for this time.

I am legally entitled to complaint since sexual harassment constitutes any unwelcomed behaviour of a sexual nature. Fortunately on these occasions there weren't any harm done and hence I've didn't want any formal complaint. I just need to think if I am confronted with worse situations in the future what can I do.