Resignation under pressure

I worked for a large company for well over a decade. About 4 years prior to leaving I was promoted and the new position did not require any overtime. In the meantime my mother became very ill and I was looking after her. This necessitated frequent visits to doctors etc. Two years later my position became redundant and although no formal offer was made they asked me to assist at a branch. I was then asked to work weekends and I told them that due to family commitments I couldn't. Soon after, at a meeting with the area manager, branch manager and myself, it was agreed that I be given an exemption from working Saturdays on the understanding that I make myself available twice a year for stock takes.

Over the next 18 months I had three new managers and frequent arguments ensued over my inability to work overtime. I was abused and life at work became unbearable. I was told frequently that I would never again get a pay rise or worthwhile position within the company. During this time if I required time off work to look after my mother I knew I couldn't possibly tell my manager, so in desperation I produced six fake medical certificates to cover any absences. My last manager discovered my fake certificates and claimed that I was argumentative, difficult to get on with and that my conduct had been a problem for a very long time. I had never received any complaint about my conduct prior to this. I couldn't take any more, so I resigned. That was 18 months ago.

I am finding it very difficult to find employment and in debt. I know I've been stupid but was wondering if there was any way I can get some financial compensation from them for the way I was treated.

To be frank, resigning after being caught defrauding your employer by faking medical certificates was a better outcome for you than being summarily dismissed. It sounds like you had a rough time of it over the past couple of years, but the fact that your response to that was to commit fraud does not give you a very strong case to pursue any damages claims against your former employer.