In other words, you really don´t have any options. Your best bet was probably that mechanics with your skills probably aren´t common. But apparently they aren´t so uncommon that the employer was willing to go through the expense and hassle of sponsoring you. It´s especially difficult to get sponsored by a company that has never done it before, since they will probably need to hire an immigration lawyer and fill out tons of forms, and then wait forever for it to get approved, if it does. It´s a bit daunting.