Join the Association for Science Education and keep up to date so you can talk knowledgably at interview. I guess you are limited in where you can apply as a single parent so it may depend upon how many jobs there are locally. Can you offer coaching in the evening to add to your income while you look for a teaching job? Read this advice about tutor work too.
Is there anything I can do to increase my chances of getting back into teaching? It's a job I loved - plus as I'm now a single parent I need a better income than as a TA. I have a science degree as well as my PGCE, and did complete my NQT time with no issues.