Jazzicatz, just wondering whether you think now that you canceled the interview because you were nervous/lacked confidence/whatever, or whether you have canceled them because you are unsure about your plans for the future?
I see that you are doing a PhD, and that working now was not in your original plan. Are you somehow sabotaging your chances at these jobs because you know that if you take on these roles you will not complete your doctorate (which I assume must be important to you)?
You must be a bright, intelligent person to have got this far. Indecision is a killer, and is stressful. Can you make a clear decision about what you really, really want.
If it is your PhD, then go for it quickly, if short-term finance is the priority then make a specific plan about how much money you need, how long you will work for ,and what the exact implications are for completing your studies. Make it like a project plan - cross off the milestones, and return to your studies.
If you are giving up on your doctorate, then do it positively and decisively - a clean break, and reflect positively on the wonderful time you have had.