From: 5 Tips for Dealing with Guilt | World of Psychology

It is not your fault things are more difficult, that you cannot find a job. You have "unhealthy"guilt about that. You are looking for a job which is what you believe would help you, what else could you possibly do?

Have you gone over the bills/money with your fiance, do you know what you all make/spend together or are you just vaguely aware of what comes in and goes out? Worrying does not help in any way and I get quite angry with myself when I worry; it's wondering about the future in ways that one cannot know. You have to accept your fiance's reassurance that it's okay that you are not working now and use all your energy in being smart about taking care of yourself (eating properly!), spending money smartly, and getting a job when you can.