Sagging suspension?

I posted, late last fall, about some damage from my tire rubbing against the wheel well. My initial thought was that it was done during a tire blow-out a couple years back (that I hadn’t noticed). Looking at it this spring, however, I note that the gap between this tire and the wheel well is very minimal (can barely get my hand in there). This makes me wonder if my suspension is sagging in some way.

I am relatively handy, but haven’t dealt with suspension before. Is this something I can examine and correct myself, or am I going to need to take it in? Any pointers on first steps would be welcome. We have a Rockwood 8312ss.

Thanks!