May I ask what kind of jobs are you applying for?
There are plenty of websites and books (available for download "illegally") that can give you job interview tips. Type down a list of all the possible questions that they could ask you, and type a polite yet succinct response. Apparently in some interviews, they ask random stuff like "Do you prefer Chocolate or Strawberry ice cream?" which are totally irrelevant to the job, and I suspect it's coz they want to see how you react to it, whether you can give a "smart-ass" reaction. Unfortunately answering these questions are irrational and taxing to our mind, but that's how these annoying interviewers go...
I dunno which country you're from, but if it's hard for you to get on welfare, it should be relatively easier for you to gain access to job seeking and job interview assistance for free or a discounted price.
Frankly awareness of ASDs in adults is still poor and many employers are still prejudiced against HFA/Aspies without truly giving them a chance at the job, instead choosing one of the myriad of NTs from a large pool, given the current economic recession.
If you can afford to, and if you believe you may have other comorbid conditions such as ADHD or Dyslexia, perhaps you could be assessed by a Psychologist/Psychiatrist and gain those diagnoses. For some reason, ADHD and Dyslexia are less stigmatized than ASDs, perhaps due to much greater awareness about those 2 conditions, and that it has become more "fashionable" in the past 20 years.
On the other hand, HFA/AS can be an advantage for other jobs, especially the low-level ones that involve LOTS of repetitive activities or a lot of personal isolation (little people contact). So in these cases, it could be plausible for you to reveal your condition but only talk about the strengths of your condition and explain why you'd be very suitable for this job.