Becoming a consultant is probably the most inexpensive way to start a new business, but remember, being a consultant means knowing a lot about one or two important things. You mention that you have some expertise in one field. That is essential. As a consultant you can use years of accumulated knowledge in one field to build a track record with clients. You may even be able to start as a consultant with your current employer. The company knows you. It knows what you know. You understand the company culture, and you know where the problems are. They may be prepared to give you a little free-lance work and that could be the beginning of a whole new career.
In the end, you have to overcome your aversion to reaching out and start cold calling companies you may already be familiar with. Speak to a decision maker and let him or her know that you are available to consult on things you know are valued by that company. Also, make sure you have a substantial resume that details major projects you’ve worked on in your field.