Short Answer: You differentiate yourself from the competition. Every product or service solves a problem. You must solve a problem the competition doesn’t, or solve it better. You provide something they do not: better product, better service, more features, extras, etc. Then they are no longer competition. In your case, it seems you have already done this. You are B2B; they are B2C.
Long Answer: Do all of the above; and add some guerilla marketing and PR - in other words - low cost, do-it-yourself, promotion working primarily in social media.
As a rule, if you are competing head-to-head for the same market share, you must match your competition dollar-for-dollar in advertising spending. If you want to take market share from your competition, you must exceed their spending.
Here’s how you market on a budget. First make sure all your marketing copy clearly states what your expertise is, and how it will benefit the customer. You want every potential customer to fully understand what problem you will solve for them. Use storytelling to illustrate your superiority - don’t just list facts. People remember stories, which means they will remember your message.
Next utilize LinkedIn, Twitter, Facebook, and YouTube. Seek connections/followers with your primary target audience. Post frequently, but make your posts interesting to your target audience. Create groups on LinkedIn and Facebook that will attract your target audience. Engage your audience by encouraging discussion. When you make videos for YouTube, tell stories - case studies - of how you solved a particular customer’s problem.
Do your own PR, and send out press releases - delivered as well written stories and case studies - to the media which your target audience attends, and a hungry media that needs to fill space may use your story as delivered.