Have you followed up and asked why you did not get the job. Was it price, Was is timing? Was it sales ability?
I think you need to find out why you are not getting the jobs? If you are losing on price, Maybe you are too high or maybe you are marketing to the wrong customers and pursuing the wrong type of work.
Give everyone here more details as to why you aren't getting the jobs, then you will probably get some helpful advice.
I probably get 1 out of 2 or one out of 3. When I don't get the job it is usually because of price. I always follow up and try to find out why I did not get the job. I'm not the highest price in my market or the cheapest, but I try to have good people skills and good closing skills. Don't be afraid to ask for the job.
Good Luck, Hope things get better