I just finished reading your thread and what struck me most was the overwhelming sense of failure woven through the narrative. Please don't misunderstand, I don't think you are failing or your husband is a failure or your marriage is a failure. What really stood out is that your husband has experienced so many failed attempts at securing a career and place for himself, which for a man can be really demoralizing. The job where he wasn't promoted, his inability to enter his program without excessive study (which he may have perceived as a failure when he realized others did not do the same), his being thrown out of the program, his inability to make money at his current job. I would be really down on myself if I had had those experiences. Now, he may perceive his ability to support your needs, both monetary and non monetary, as failing.
I would hypothesize that, assuming he is genuinely a decent fellow and not an emotionally abusive a-hole, after all those failures he is likely have latched onto either an internal or external reason for this pattern of experiences...either decided that there is something wrong with him - not smart enough, not skilled enough, etc - OR there is something wrong with everyone else - people don't understand him, give him a chance, give him the credit he deserves, everyone is out to get him. Either way, he has probably given up much confidence that he has any control over his future and fully expects you to leave him, either because he isn't (I don't know what he may lament about) smart/skilled/charismatic enough to maintain the relationship or because everyone is out to screw him. Either way, hoarding money makes perfect sense.
If I am totally off the mark, just ignore me, but it sounds like his hoarding and withdrawal and unwillingness to try things is related to some mild depression. Many times, though certainly not always, this can be related to or exacerbated by someone believing they have no control over their life course, which is not going the way they want. The hoarding and such would be an attempt to maintain a little influence over the outcome.
Also, maybe convince him to go to therapy for a couple sessions. Like a month. If he doesn't like it or there is not enough of a defined goal, he doesn't have to go after that. Don't go to your therapist, get a good recommendation for a therapist who is goal oriented and focused on outcomes. Likely, your husband will actually enjoy the experience. Therapists purposefully help rebalance the dynamic in a way that both people are able to find power in the process.
Best of luck!