Tier 4 Dependant Visa

Hello guys, I need a huge help with this issue.

The company that has been sponsoring me for the past year shutdown two months ago and i lost my visa in the process. A company that offered to sponsor me just informed me today that they are unable to continue.

However, my girlfriend of almost four years and I have been staying together for the close to two years. She is currently studying on a tier 4 visa and working part-time. I realise now that I may be able to be a dependant on her visa. All her fees and maintenance is sponsored by an international company and I just read that the company will have to have it in writing that they are also providing funds for any family members or dependants. In this case, I am assuming that even though we are not married we should qualify under unmarried partnership.

What will be the steps involved in this? Is this likely to work?.Considering we can have the company write an official letter to confirm that my maintenance will also be covered.

Please, any help will be appreciated.

Hello. Can anyone help with this?
Thanks