Will my credit ever heal?

I've made a lot of financial mistakes - when I first moved away from home 6 years ago, I charged a lot to several credit cards due to medical bills, school, and quite frankly - lack of financial responsibility and planning. I am more financially stable now, and am working hard to pay everything off. However, everything sat for years (on the horrible advice of a debt counselor) and went to collections (we were going to settle everything). Their company went out of business, so I am left to clean up the mess myself. Bottom line, I am picking one credit card at a time, and trying to settle before it reaches litigation. I am also paying on my medical bills. When I look at my credit report, it is a mess, with the accounts all stating, "Account closed, transferred, seriously past due . . . legally settled below owed amount . . ." etc. What can I do to at this point to make my situation better? My boyfriend said to get rid of my credit cards, but they were closed out a long time ago. I've been "cash only" for about two years. I know it will take time, but in the meantime what can I do? I'll be 29 in August, and it's not like I have unrealistic expectations of buying a house at 30 or anything - But I'd like everything cleared up on my end by then at least!