I would not do Java in your position, too much competition. Find out what well paid programming jobs are available in your area. Good SQL Development/Report writing jobs would give you what you are after and is a relatively simple logical language than anyone with an engineering background and the correct working attitude could become proficient inside a year.
SQL jobs seem to be in demand at the moment as it’s not seen as a ‘cool’ language and generally requires good people skills to deal with management as well the technical aptitude. These are things that an older, non-graduate will do well at as you’ll have well developed people skills. Also you can generally get a job with any background as it’s skills tested at interview but you will need to start with a ~£25k job.
I’d second this. SQL is massively easier to learn than ‘proper’ programming and there is widespread demand. Also look at reporting tools like Tableau or Qlikview. Again they’re very easy to learn, in demand, and because they’re relatively new nobody can claim 10 years experience with them.
If you’re very mathematically inclined take a look at R. ‘Data scientists’ (like statisticians, but different) are in incredible demand right now, and there’s an easy way in if you’re talented and willing to work at it – enter some competitions on Kaggle. If you do well consistently you’ll build a reputation and start to get job offers. If you actually win one (impossibly difficult) you’d be looking at over £100k.