To be honest I don't think you should be discussing the merits of going back to work vs childcare costs with the SW office. Even if the individuals are sympathetic, it may come back to bite you if you are classed as 'unavailable for work' so don't put yourself in that situation.
What you may want to explore is SW support for doing some courses and improve your qualifications. Then you can aim for more money and can ensure your career does not suffer.
Alternatively, if you are talking about a career rather than a job, you may want to pay all your money to childcare for a few short years in order to preserve your career progression - depends on the job but it is a very stressful way of doing things.
Diziet