That maths degree probably means, at the least, that you're comfortable learning graph theory, combinatorics, discrete optimisation, probability theory, etc. These things are the foundation of systems and computational biology.
The software development skills are also sorely needed - a huge proportion of computational biology software is unusable outside of the lab that developed it, and well-engineered software underpins a LOT of successful research. Many great ideas go wasted due to lack of good programmers to implement them properly.
I would say there are two ways in:
1. Stay in your current job, and do hobby work collaborating with scientists to write scientific FOSS and publish it. If you're interested in this, I have a long list of ideas.
2. Transition to science - get a job in a bio lab or at a computational biology/genomics institute. Depending on the specific problem you want to work on and where in the world you are, I can suggest places.
Probably 1, then 2 would be a good idea.
I live in the Boulder, Colorado area, and I've even applied recently for a job at a biotech firm. There are plenty around here. Only saw that one job opening, though.
Beyond that, I just don't have the vision or lack the key insight on where to go or what to do next. That's where your item (1) would come into play, I suppose. I need to be guided. It's a difficult position to be in. I'm basically saying "I have skills and want to contribute, but need a step by step guide, and probably continuing guidance along the way, before I can contribute anything valuable."
Feel free to get in touch with me if you'd like to chat.