FYI, Alan J__ (the RBA) provided your email address to me so that I might send you an encouraging note following your DNF on the brevet last week.
We met and briefly chatted before the 200k brevet last Saturday. (You asked whom you should tell not to worry about you; I essentially responded "volunteers, or anyone that asks." I also pointed out Mike D__ to you, but I don't know who introduced you to MikeD.)
From Alan (& from the results published on the RUSA website), I understand that you DNF'd on the brevet; I don't know where or why.
Do NOT let that DNF dissuade you from having another go at a 200k event. Also, do not be put off because you had to ride whatever-distance-you-did-ride solo; I have had many enjoyable solo 200+ kms rides as they are usually very peaceful journeys. If you learned something from the ride, then the ride was a success, even though you had to DNF. (As an aside, last year a young non-RUSA-member rode the Spring 200 brevet, mostly solo -- his last 50-miles was certainly solo. He was not worried, and he did finish. At the finish, he noted that it seemed to him that the last 25-miles equated to being half the ride -- the first 100-miles had been relatively easy, but he had to work both his legs and his MIND to get through the "second half" of the ride, that is, the last 25-miles.)
When you told me that your long ride prior to the brevet was 50-miles (back-to-back 50-milers, if I recall correctly), I did think you may have been asking your body and MIND to make a rather large leap, but you were confident and the most important part of this sport is usually found between the ears -- the determination, the calm when things are going badly, the joy when things are going well or even just so-so -- those are often more important than how your legs or hands or feet or butt feel.
Some people have shown up for their first successful brevet with prior career long rides of 70-miles, and even 50-miles, but most have done at least one century previously. I am going to assume that you will try another 200k brevet, or perhaps a 200+ km Permanent in the next few months. More than assuming that, I'm encouraging you to plan for that.
As part of your plan to successfully complete a 200k ride, I suggest that you (and your girlfriend) do some of the local Permanent-Populaires. I assume that you've checked out the Permanents page on the RUSA website -- if not, I encourage you to do so (& I won't describe Permanents here, except to note that Brevets are EVENTS that occur on designated dates on designated courses whereas Permanents are designated courses that may be ridden on any date agreed to by the rider and the "route-owner"). As you may know from perusing the RUSA website, RUSA populaires are 100-199 kms in length. Most permanent-populaires are slightly over 100k in length, and make good training courses if one is interested in doing a 200k brevet; populaires are also excellent rides in-and-of themselves.
Populaires typically take only half-a-day to ride and often other RUSA members will also be doing the route on the same day. There may be a better chance for camaraderie on half-day populaires than may occur on brevets (or Permanents of 200+ kms).
I recall that you indicated that you lived in the Garner / Clayton area, but that you and your girlfriend also do rides from the Durham and/or Chapel Hill area. With that in mind, let me suggest three permanent-populaires ("pops" for short) that start near Garner (and are not as hilly as Alan's brevet course):
Get 'er Dunn, 102k, for contact information (click here), for a map (click here);
Benson Mule Pull, 105k, for contact information (click here), no map at this time;
Lillington Lilliput, 123k, for contact information (click here), for a map (click here).
There are quite a few other populaires in the Triangle are. I leave the search for them to you. Some of them are about 85-miles in length -- that distance may be a good thing to do before having another go at 200+ km ride. An informal 100-miler, or an organized charity century, may also interest you as part of a plan to tackle 200 kms again.
Before having another go at Alan's 200k brevet course (in August), you might like to do a 200k ride on a course that is not as hilly as the brevet course. I'll not include contact information for likely suggestions of that distance; however, if you do the pops near Garner, you'll figure out how to make contact for two flatter 200k routes that start near Garner.
Lastly, most randonneurs have learned, and will tell you, that "things" happen on 200k rides that don't happen on 50-milers or even 100-milers. If you find that you like riding 200 kms, we would all assure you that "things" will happen on 300's, etc. that do not happen on 200's. Most of the "things" have to do with your body and MIND and comfort on the bike; some of the "things" have to do with mechanical failures, but mechanicals can be minimized with good maintenance prior to the ride; the body and mind things -- well, those have to be personally experienced -- luckily, some of the "things" are good things.
Good luck, and I hope to see you again on a future rando ride.
Above all, be sure to
Enjoy the ride