The only advice I have to add to that above - have you approached local SMEs? They probably won't be able to justify employing a Social Media specialist in-house, but are often too busy running their business to do it themselves.
If your writing and graphic skills are good enough then you could offer something like 2 posts per week on Twitter, Pinterest, Instagram and Facebook for £75/month. You'd need to ask them each week for any news or things that they'd like to promote, and probably write a summary of weekly activity. It'd be a nice little service for specialist shops, cafes, etc.
Perhaps look for businesses which have social media profiles but don't keep them updated.
Social media workers tend to be in-house customer service reps, as Chammy said, or more on the marketing side - with the latter you''ll be increasingly expected to have good graphic editing and video skills to complement creating posts. Pitching to businesses rather than accepting a job means that you can design the 'job' according to your particular skillset.