Forum Support Boiler problem

I'm pretty sure I know the response but just thought I'd ask.

I have a Halstead Trio Boiler. Probably best that I bullet point.

- over 20 years old
- was a reconditioned one when installed
- it was working til last night
- 4 radiators
- 2 not been used for years
- bled the used ones
- was slowly working last night
- hadn't turned off when bled (didn't know I had to)
- now pressure not working and temperature only reached a maximum of 26°
- filler loop seems ancient and unlike any pictures I've been able to find.

Advice needed. Broke and can't afford new boiler. Absolutely freezing lol

All help greatly appreciated