I think you should put on your sales hat. I know you said that you are the "coder" and your partner is the sales person, but I think you should start selling and supporting them. Trying cold calling and cold emailing. Use some money for a marketing push.

Use the stress of your short runway to push you to sell. Every conversation you have with potential customers should be about how you can get them to pay. Talk past their requests for features or whatever, something like "This is a great feature that we are working on for you and if you sign up for a year's service, we'll discount you until the feature is delivered".