What should I do if I cannot afford a journal Article Processing Charge? I would like to publish an article open access, but I cannot afford the article processing charge (APC). I am based in the UK, so I do not qualify for some of the available fee reductions or waivers. I also do not have grant funding to coverage the fee. How can I obtain funding to cover the publication fee to make my research open access?
Where are you based? If you're at an institution, I'd get in contact with your library. They usually have funds of some sort to cover APCs these days.

Depending on where you're submitting, it is still possible to get a fee waiver if you can provide financial justification (which it seems like you should be able to do). I don't know how well this works at most journals, but those like PLOS ONE and PeerJ are well known for providing fee waivers for researchers with OA support (apart from a couple of incidents).

Alternatively, you could pursue the 'green' route of OA. Submit your paper, but don't make it OA (via the 'gold' route), and self archive the pre-print, post-print, or whatever the options available for your journal are. You can check policies here: http://www.sherpa.ac.uk/romeo/

Try playing with these options a bit, and then report back if there are further complications or details to add.