Everything is high risk

So... I have a small business where I am a mobile mechanic. Insurance is driving me crazy. I tell them I do some welding and that is the end of everything. I told them I change tires on farm tractors, and I am told it's high risk, I told them I sit in a truck and inspect fence post...and it's a high risk. this is driving me nuts!, I have been a welder/mechanic for 35 years. I have never had a claim against me, nor has any companies had to claim against me. I want to be on my own, but I need insurance. Are there companies out there that insure mobile mechanic services? I am in Southeastern PA. Thanks