We have sort of similar stories in that I delivered my son early (29wks) in 2009 and am now going to try to conceive again. My husband and I agree that we want another child, and in the abstract are willing to go through the risk, but the funny thing is, I was just cleared yesterday by my endocrinologist that my hypothyroidism is under control and I can begin ttc now, and after initially being happy and excited, my husband and I BOTH started to get heavy and panicky ----- already!!! and we haven't even gotten pregnant yet! I told him this morning that we have to figure out how to deal with this anxiety bc it's going to be a loooong road!
So I guess this is more of an empathetic message, but you're not alone out there. If you look around on this site there are many women who have gone down this road, many who've had successful pregnancies after HELLP/Pre-E, and those who've had reoccurences. The best thing to do is get a consultation with an MFM in your area, s/he should be able to give you a ballpark percentage for recurrence. Mine has been very encouraging to me to try again, and I use that encouragement to "calm me down", although I know nothing is guaranteed.
I do wish you the best through this process of deciding is you want to have another, it is not an easy decision AT ALL!