Help, should I hire a layer for another I140

My DIY NIW I140 has been pending for six months. I have left my research job position in a university and taken a new job in a big company. I am thinking of re-apply another I140 because of changing job and also suspecting that my petition letter was not well-written preciously. It is regretful that I may waste the very strong recommendation letters I got for my pending I140.

Looking foraword to suggestions from experts like Xiaobaitu and mytwocents.

Thanks