Career and relocation advice for a young individual

I'm almost 25 years old and having just started my career in South Africa (hometown). I've spent a year travelling abroad and then came home to settle and begin my career. I've already hit the ceiling in my career and despise every day. I studied chemical engineering at university but now my day-to-day job is filling out excel sheets with minimal pay. I would say I depressed. I've recently been granted a visa to work in Australia and saved up enough money to relocate there. I've had a few interviews online with some companies but I'm struggling to gain some traction. My work visa ends in July so essentially I've have to leave soon if I were to make use of it. I have a small amount of distant family there but otherwise I know not one soul there and my relocation would be completely just me. The issue is I want to get into a different industry and a lot of people give advice that I should change careers here at home where it's easier and I know people (I've recently been offered a great opportunity at a startup here where a friend works) as opposed to taking a long shot in jumping career paths in a completely new country. I somewhat agree with this and so if I went I would simply be going for the sake of my visa - getting another work visa would be extremely difficult. I also have a long term girlfriend here and my immediate family. A part of me wants to stay here until I have everything on track and I'm happy with my career and daily routine. But a part of me misses the excitement of travelling to a new place and adventuring while I'm still young. Going to Aus is very risky (my home currency doesn't go far in Australia) and I'd be sacrificing a lot for it (basically everything - career, girlfriend, friends, family) and my fear would be that I end up at another dead-end job there as I would effectively be a foreigner. Also, I'd be missing out on an amazing opportunity to be a part of a startup. I have a number of days to make the decision and my head is hurting just thinking about it. What would you do in my decision?? Thanks for the advice!