Finding a company to sponsor you is going to be pretty difficult they have to do a lot of paperwork and prove to the INS that they cannot find a US citizen that can do the job. That means advertising for the job and finding no suitable applicants. Getting them to fill out the paperwork and advertising may be difficult enough in its self, what motivation do they have.
Marrying a US citizen is the easiest way to go but even that will take approx 2 years to get the "green card" however you will have employment authorization about 2-3 months after you file your adjustment of status paperwork(Form I485)from J1 visa to alien resident. Assuming you will want to leave the country a some point(maybe to visit home or even work an international sector) you will also need to file for advance parole(travel authorization)Form I130.
Hope this helps, to answer your original question, yes, you are wasting your time at the moment with your current visa.
From a fellow Brit(married to an American)
FYF