Welcome to the Bee! This got longer than I intended it to be, but hopefully it’s useful to you!
I don’t think there is a way to suppress the waiting itch, unfortunately. . .
I am in a somewhat similar situation. I’m in grad school, for which I am 3 hours away from my SO for most of every week. We’ve been together for pretty much 4 years too, and I also have the wedding itch! But the fact that I’m in school and earning barely enough to scrape by has things on hold I think. I also feel like it’s the one subject I can’t bring up directly, which is very annoying. My SO and I have talked about it before, discussed possibilities for our future, etc., and we know we want to be together forever, but somehow my bringing up engagement/marriage stuff feels awkward, so I’ve been trying to limit that as much as I can. It bothers me that it seems to be a taboo subject, in a relationship where my SO and I share everything else (and I do mean everything, other than details about exes, which we just aren’t interested in). My solution is waiting until after our 4-year mark, near the end of this month, to ask about the marriage subject again. Because not talking about it isn’t healthy.
It sounds to me like your feeling that you cannot talk about marriage and future stuff with your SO needs to be addressed. It’s scary and sometimes stressful to bring things like that up, but it’s only fair that your and your SO be on the same page as far as knowing how each other feels about such an important issue. Is part of the reason you haven’t been talking about it as much might be because of the long-distance thing? Perhaps one or both of you are privately concerned that because you are long-distance, things might not work? I’m not saying that they won’t, of course– but do you think fearing that the long distance won’t end is part of the reason he’s not talking about your future anymore? Sounds like that’s something that needs to be talked about and clarified.
How about asking him outright how he sees the next 2-4 years going for him, and for you as a couple? And letting him know that for you, in the next however-many years, you see the two of you making a commitment to living close to or with each other, and getting married. Or if you feel that bringing marriage up outright will be too much at once, ask if he sees the two of you being together indefinitely. Then at some point after that, if he answers favorably, ask him his thoughts on getting married.
Basically, the key is to communicate! It’s so hard to get up the guts to talk about this stuff, especially with long distance and living in separate places and being in school/not knowing where your job will someday be! I SO understand how you feel! It really sucks sometimes. . . .