Sad because i am thinking of those i've lost again?

I should begin by saying I do not deal with death/loss particularly well. As the years go by it gets a little easier for me not to get as upset about it but there are still things that remind me of their loss and then I get sad again.

I've lost my father,both grandfathers, any great grand parents,my one grandmother and my pets who I all loved as much as any human family member. I lost my dog and remaining grandfather last year and still don't feel truly okay over their loss at this point.

There's this one commercial on tv about some kind of heart disease perscription that prolongs people's lives who would otherwise die,and they have these old people in it singing a song that goes like "I love you tommorrow" and thats been making me really sad when I see it lately. There is no tomorrow with those that i've lost and one of them died of a similar condition that this medication is for.

I don't get like this every day or even often but these past couple of days i've been really sad lately. Is it bad to be this way? I'm 22 but i've kind of always been a really sensitive person.