The only way you can meet her is to apply for a TRV. That said, if your purpose of visit is to meet your girlfriend then a TRV refusal is most likely possible (based on what we've seen on the forum). I had already mentioned that your chances are on the lower side due to your age + salary paid in cash + no strong ties, etc.
You can still apply if you have solid documentation in line with what I have suggested earlier in this thread