You have other options you can also try:

1. Try to get a raise at your current job. Are you being paid fairly, given experience and other people's salaries?

2. Try to switch to better paying job within your company. If you have additional skills, maybe you can switch to something where you're a little less qualified. Since they know you, hopefully they will trust you to be able to learn new things.

3. Apply to entry level developer jobs elsewhere. "Formal qualification" matters less than skills and willingness to learn to many companies.