Sorry to hear you are having difficulty finding a suitable position. It takes a while to find the right opportunity. I had similar experiences when I started out. Architecture industry in the UK is very competitive. Keep at it and you will pull through!
I would say apply for following roles:
1. Architectural designer
3. Architectural assistant Part 2 or equivalent ( although by equivalent they probably mean prescribed examination qualified)
4. Architect/Designer (when you see designer added to this, it means they are looking for a chartered architect but are also open to 'designers'. A designer could be an architectural professional. However they may not have gained the chartered status in the UK)
Focus mainly on 1&2 and may be also 3 when applying. 4 is mostly looking for UK qualified architectural professionals.
Don't exclude any application because you don't fit the bill. Currently we are in an employee's market. There is skills shortage across industries. And you might just find a right position coming your way.
Do present a strong portfolio. And make sure you are well versed in Revit.
Good luck on your endeavours. I wish you all the best in your job hunt.