Salve Fiend of the Fell!
Congratulations! And by all means do continue.
I've been wondering, too, about motivation. Sometimes the going gets tough. Right now, for example, I am reading Eutropius' Breviarium in its entirety as I believe that sufficient amount of reading is paramount in learning any language. However, after a while the accounts of various emperors, the duration of their rule, their crimes, etc., tends to get boring. Boredom is (besides an overly difficult text) for me one of the biggest enemies of learning. Another one is a text which is too difficult. Upon first trying to learn Latin I immediately started with Caesar's Bellum Gallicum after finishing Wheelock's Latin. That turned out to be an error as I was not yet ready for its difficulty. The net result was that I quit.
How to stay motivated? In the case of boredeom I'm coping with it by switching for some time to another text about something completely different (reminds me of Monty Python) or concentrate on another area, e.g. instead of reading texts I'm concentrating on vocabulary or grammar.
As for switching texts, I read the Nuntii Latini on a regular basis as it provides Latin texts of a vastly different sort, both as far as subject matter and vocabulary are concerned.
One thing I do have learned over the time is that one thing is paramount: whatever you do, do it regularly. Putting Latin (or whatever) aside for a longer stretch of time is highly dangerous, and in the case of Latin even more so due to its difficulty. "Use it or lose it", that's the motto. So, should that ever happen, do continue, albeit a more leisurely (and less time-consuming) pace, just enough not lose the competence you've already acquired. Otherwise it would be regrettable waste.
One thing I would like to see is an e-mail letter (perhaps once a week) sending a brief (but not too brief) Latin text to the subscribers (like Merriam-Webster's "Word of the Day"-newsletter), switching between different sorts of texts. I definitely would like the Nuntii Latini to be up for subscription as I sometimes forget to read them.
But returning to your original suggestion... I believe that as far as back-slapping is concerned the most important person is...oneself. So do praise yourself when achieving a milestone, etc. I know that may sound kinky, and it is certainly something not encouraged by the gloomy, dreary religions. However, if you do not praise yourself, who will? Of course, a certain amount of realism should be present.
A question to the other forum members. Under what circumstances do you have problems with motivation, and how do you deal with it?