When do you decide that it's better to give up chasing a goal/dream that doesn't seem to be materialising?

I'm really struggling lately, career wise.

Over the years I've invested in myself and my own CPD. I graduated with a BA Honours in Business Studies, and really enjoyed the HR Module, which is why I chose to go down the HR Route. After finishing university I found myself unemployed for 8 months. I originally came from a retail management background. I was lucky enough to secure a part time reception job, my aim was to take on this role purely to fund my Level 3 CIPD qualification which I successfully completed last year. Alongside working this part time job, and studying, I secured a HR voluntary placement in a manufacturing company before I then successfully secured a full time Clerical post in a HR team for a local authority. I have been employed here now for almost 2 years, and I have come to a standstill in regards to learning and developing. My managers are fully aware of how I am currently feeling. I have supported HR business partners on he odd occasion through disciplinaries etc as a note taker, but overall I'm feeling really stuck. I cannot seem to secure a HR role due to lack of experience. I have requested to shadow and get involved with others at work, but unfortunately my requests to do so have been unsuccessful. I am contemplating progressing onto the level 5 CIPD course in hope that his may help my current situation, and hopefully make me look more attractive to employers, however, I worry that the problem will still be the same (lack of experience).

I am stuck in a vicious circle and my question is, are there any other people who feel/felt the same?

And how did you get out of the situation before feeling like it's time to give up and look at other options ?