It sounds like your mom means well and supports your efforts, but you sometimes catch her in a bad mood and she takes it out on you. That's unfortunate, but it happens. I know how frustrated you are, but try to see her point of view as well. Imagine that you've had a crappy day for whatever reasons, then you realize that on top of everything else, you've lost your checkbook. At that moment, your adult daughter calls and asks for money. Even if you're happy to give it to her, the timing of the phone call sucked.
As far as job hunting goes, I've never understood why people spend ANY time jobless while looking for another job. I would take a stupid retail or restaurant job now so that you have some income coming in while you're looking for a real job. Then just keep looking. Your mom is right that job searches can take quite a bit of time, but you need to take care of yourself while you're looking. Just don't settle for the temporary job - keep aggressively looking for a job in your career field until you find one.
Just one question about the financial aspect of all this: If you're engaged and your FH is moving in with you, why can't HE help you out financially? I know that some couples like to split bills 50/50, but if one person is employed and the other is not, that makes no sense. Since you're getting married, now seems like as good a time as any to practice making things work on your own, including one person assisting the other in a time of need. I supported DH for about 6 months while we were engaged when he was job searching, and again for several months after we got married when he had to have several knee surgeries and was out of work on disability. What would you do after you're married if someone lost their job? You'd have no choice but to work it out.
Vice President and Guardian of the Toilet Brush of POOP: People Offended by Offended People