I'm very sorry this is happening to you and your beardie, I want to help you but I'm still confused as to exactly what you think the issue is. I guess he hasn't pooped in a while, but how long since he last pooped? Does he have a
black beard? Is he straining to poop a lot? Usually when they are very impacted they will start straining to go a lot, they swing their pelvis/hips back and forth and stand like they are trying to go. Sometimes they even get a curve or a hump in their spine, and often they loose some feeling in their back legs and have trouble moving them, like they go limp. And a
black beard is also very common, especially when they are straining, as it is painful. As already mentioned do not feed him any more solid food if he is impacted, as it will literally just sit in his stomach/intestinal tract and rot, causing infections and other issues. Only liquids and liquid foods like prune baby food mixed with raw, canned pumpkin and some unflavored Pedialyte. You buy a jar of prune baby food and a can of plain, raw pumpkin (with the canned vegetables at the store), and a bottle of unflavored Pedialyte because he's dehydrated and needs the electrolytes, the generic Walmart brand Pedialyte is fine... dump the entire jar of prune baby food into a Tupperware container that is able to be microwaved, then add 2-3 spoonfuls of the canned pumpkin, mix it up, and then add in the unflavored Pedialyte until the slurry is thin enough to be sucked up into an eyedropper or an oral syringe. Mix it really well, and microwave it for 45 seconds to warm it, mix it really well again and test it on your wrist, it should be warm but not hot. Try to get him to lick at least 2ml of it off of the end of his snout (2 eyedroppers full or 2cc's on a syringe, more if you can get him to take it, he needs the fluids). The canned pumpkin is a very good natural laxative....
I'm not exactly sure that an impaction is his issue though, we don't know your UVB lighting situation or the temperatures in his enclosure...And my major concern to start off was that I was under the impression that he was sick because you hadn't been feeding him enough. I'm not asking this to criticize you or anything, but rather to be able to help you, it's very important that if he is actually sick due to malnutrition that he be fed the correct things and that it happen very slowly, because if he hasn't been eating for an extended period of time to the point that he's now sick because of it, if you feed him a bunch of solids and protein all of a sudden he can actually get much more sick and his body can actually go into a kind of shock, where his kidneys and liver cannot handle too much at one time...That's why I'm asking you what the actual problem with him is, as you mentioned in your original post that "you can't always get food for him", so if that's actually what the issue is then we need to know...I mean, how often recently has he not had food? I'm not sure how to ask the question, I guess I'm asking what you meant when you said that, like in the last month how much has he been fed, how long has he gone without eating? And what are you feeding him when you are able to get him food, and how much does he eat? Is he really thin, like emaciated?
Again, I'm trying to help, we all are, so it's important to try to figure out what the actual problem is if we're going to try to save him, and if you can't take him to an experienced reptile vet, which is what should be done immediately, then we can at least try to help. I just don't understand exactly what you meant by what you said, and if you meant that this is why he's sick...
A photo of both him and his enclosure/lights would be extremely helpful to see what we're dealing with here...He should go to a reptile vet right now, but I understand that you cannot afford to take him. All I can say is that if he is in pain like you think he is, he's suffering and needs some help, so we'll try, but if you can borrow the money please take him to a reptile vet...Try applying for CareCredit online, all vets take it...But if you can't then please try to explain the situation and post some photos, and we'll see what we can do to help him..
This is very critical at this point, especially if he's in pain, so try to post quickly...