Good luck on the next phase then!
However, since other people probably won't say it - I don't really get the point in "officially leaving" a forum like this. If you're really busy you will naturally spend less time browsing, posting, doing whatever it is a proper community member does here, but I don't really feel like there is ever much point in pre-emptively decide you're going to be so busy you are going to have to leave. If you've got any time where you're not doing work (and probably will, no matter how busy you think you'll be), there's no reason you can't spend a bit of that time checking on DTF or any other internet community / site you like. Or at least, no reason to officially rule that out as an option - if you end up spending your limited (and hence much more valuable!) free time doing better or more productive things then great! But I think (and based on what I've seen of other people claiming to leave forums / the internet) that's just something that happens naturally rather than something that happens when you suddenly decide to stop "cold turkey". I'm sure there are active members here who have commitments that keep them just as busy (not saying that you'll want / be able to do that, just that it's not automatically impossible because you've got a lot of work to do) but are very prominent members of the community here.
But that's just my own take on it, you will know better than anyone else what'll be most helpful for you. Good luck in your studies, and in case you actually do leave then it will be a shame not to have contributions from one of the more memorable posters.