I stayed at home for 5 years on IS until my son was starting school.
I live in a rural area and while I was well qualified any job would have meant a fair bit of travelling which for me meant time away from my son.
I was in fact offered two jobs just after my ds was born. One was a job with the company i had temped at while pregnant, but it was full time and an hour drive each way. The other with a small local business but would have involved traveling every three months or so and being away overnight on these occassion.
Neither of these was an option for me. I was bf at the time (did for 18 months), plus lack of adequate child care locally, little family support and several other factors, not least of which was that I had always wanted to be a SAHM meant that I stayed home while he was small. It was very hard finanically.
When I did return to work I found a part time job easily (at our local play group) which covered the 16 hours I needed for WTC and CTC. After a year there I was ready to look further afield. I was very lucky to find a very flexible employer who lets me work flexible hours without too much issue.
I was back on the bottom rung of the ladder, but I still work at the same company and my son is now 10.5. Life is still a bit of a struggle, and I am stuck in that 'capped' limit where I am not actually any better off working more hours (possibly even worse off!), but we are so much better off now both in terms of money but also that quality time we had together at home when he was small.
I no longer have to worry if I have the money for the bills when they come in etc and we can afford to go on the odd (cheap) holiday.
My advice to you is you have to good look at your situation and decide what you want in terms of your life and what you are able, willing or prepared to either live without or willing to do (in terms of childcare and time away from your child) to have the kind of lifestyle you want. I had no debt to consider and counted every penny and went without on many occassions. I'm not talking nights out, clothes, shoes etc, I mean food. My one luxury was my car and I did stress over whether I could afford to keep it (living in a rural area it was my only means of getting to shops etc without expensive taxi or infrequent buses). Even though I rarely used it the cost of insurance, tax etc was a huge chunk of my budget.
If you have a big cc to pay off then clearly that is a major factor in your decisions about returning to work. Go see your local CAB for advice on that. They may be able to get a freeze or lower interest rate for you in the short term.
Also are you getting anything from your ex in terms of child support? This will be taken into account if you claim IS. I didn't so it wasn't a factor for me. You may find you are actually better off working, claiming WTC & CTC and keeping the child support if you do.
The lone parent advisor at your job center may be able to help you as well. Mine proved invaluable when I first returned to work and helped me work out just how much better off I would be.
Good luck with whatever you decide to do
Gilly