Off sick again!

Up until December, I’d only had two days off sick in the four years I’d been in my current job. In the last eight weeks, I have been off sick three times as well as having time off on compassionate leave. It seems that my immunity has been completely shot to pieces ever since my dad died and I seem to be picking up every bug that is going around. I’m getting a bit bored of coming down with things and feeling rubbish this winter. Can I have my normal immunity back please so I can get on with life?