Georgia,
I ran into the same bumps in the road. An inconsistent marketing plan was almost my demise. Luckily, I decided to focus my marketing strategy and I was able to land three deals over the next 2.5 months.
My strategy was to market to about 1000 names & mail them at least 4 times.
I used yellow letters because the verdict on BP is they get a better response rate. I now 100% believe this. What ever you choose measure tsuccess by the amount of calls that you get. Starting out you will be able to close 1 out of every 30-50 calls. So the key is consistency. And focusing on the amount of calls coming in. I always ask my self: what do I need to do to get 30 more calls? Rather than: what do I need to do to get another deal? Once calls are coming in deals will happen.
One deal will make up for all the money you feel was lost. Until then it is normal to feel you are wasting money. Be consistent and you will be getting deals left and right soon.