If you think a lawyer is too expensive, perhaps you should ask a lawyer about costs before deciding against legal assistance or delaying assistance until later. Great innovative ideas occur in everyone all the time. Very few of us actually take that idea and transform it into intellectual property. In the Information Age if the idea occurred to you it is likely to have occurred to a number of others. Creating intellectual property is often like a race, with the winner obtaining the rights, and all others gaining little or nothing.
Simultaneous invention is very common.
Good examples are calculus, the telephone, and ceramic superconductors. If you are not actively taking action to protect your intellectual property, then it is probably at risk. The greater the commercial value of your intellectual property the greater is the risk. Interview with firms until you locate one that is experienced, understands what your objectives are, is responsive to your needs and which can grow with you as your property interests mature. When in doubt, interview, interview, and interview.