I'm returning to study soon as well. I hope to do better this time now I know about my aspergers and anxiety but there's this small fear niggling that the people who tell me I'm just lazy are right.
I know what you mean, there's been so much negativity directed at us, "you're lazy", "you're incompetent", that it is hard to get those voices out of our heads. I go through that at work a lot. What makes it even more difficult is that it is a burden we must carry alone, we can't tell anyone about it because most people don't understand.
I am going through a difficult time with a co-worker right now. It's a long story, but I feel that she is judging me because she feels that I am not taking care of my responsibilities. For example, we have a shared e-mailbox. Now, I am not one of these people who obsessively check their e-mail and phone every five minutes, and especially if I am on a project that requires a lot of thought and attention to detail (and I get a lot of those!) then checking my e-mail is definitely the last thing on my mind. Well, I "missed" an e-mail. So she tells me that it is not her responsibility to answer my e-mails (I don't recall asking her to!). She also got on me about something else that I apparently was not doing and hadn't been doing for some time (but only came up now) and she said, "Can I trust you on this?" I looked her right in the eye (which you know does not come natural to an Aspie) and said, "If you are asking that question you already have decided what the answer is, and the answer is, no. I will not have that burden on me, I will not play that game. Either let me take responsibility for that task and let me handle it the way I see fit, or do it yourself." I meant it too. If I am that lazy or that incompetent, then management knows how to handle it; if I am not, then get off my back. I have to add that this was not a supervisor saying this.
So: if people think you are lazy, then let them deal with it. In my experience those who are being the most critical are not the people who are in a position to deal with it, they are just blowing smoke and trying to manipulate you into doing what they want. The last thing they want or expect is for you to call their bluff.
Besides all of us are a little lazy at times, that is human nature.