Keep in mind the intent. In almost all cases, they are genuinely trying to pay you a compliment. The assumption they are making, right or wrong, is that you have chosen to undertake a course of action toward a goal and they are recognizing that the path you are following is not easy but that you appear to be succeeding. In most cases just saying, "Thank you," and then continuing with the prior discussion will naturally end this one because to continue it they would have to go out of their way to bring it back up and most people would find that sufficiently awkward that they will just let the matter pass.

Of course, some won't. Some of those will want to focus on you, for one reason or another. If you don't like that, then just say something like, "Again, thank you, but this is a very personal journey for me and I'm just not comfortable talking about it. Maybe sometime down the road, but not now." Then again turn the conversation back to where you want it. If they still persist, now you have justification for getting increasingly pointed.

But also keep in mind that many people that bring it up again are not so much interested in you and your troubles and successes, but rather in learning about what you have done and are doing so that they, or someone they care about, might benefit from it. There's nothing that says you have to help them, but when you were looking for a path to follow, wouldn't you have not been very appreciative of the perspectives and advice of people that were apparently succeeding at what you wanted to do? If that appears to be there motivation, then I would recommend talking to them, just keep the discussion focused on the plan and the issues surrounding it and keep references to yourself to a minimum.