September goal with others involved. Maybe not…

I’ve chosen a goal for September that’s not really working. In the sense of it does involve other people; I chose “house sold by September 30”.
It’s on the market for more than a year. We get potential clients with the international real estate agents to visit but no offer yet (10 visits). This month I do even more (besides the work of the agents) than the months before to get the house known in potential niches. Doing so, means posts on fb, making video’s pics, story’s, and much more. Also being courageous and asking for sharing that I normally never do. With the thought: “anyone can think whatever they think of me, and that’s okay”.
Thursday we got a call form the real estate agent, a couple from South Africa wanted to visit our house today, Saturday. I’ve our house constantly organised and clean, but before a visit I get my prepare-visit-schedule out and do even more, the gardener will come, I buy more flowers etc etc. And then, yesterday night we got a call from . The agent; “they decided to go back to ZA and see when they will have a chance to come back”. Another time the agent found out an Italian potential client didn’t have the money in the end. I get it. It’s nothing exceptional. It can happen. We never know how long it will take. What I notice is that this selling process, combined with my ‘normal work’, my business, family life, and a construction project is taking it’s toll. I know, everything is just a thought.
At the moment I recognise my physical state as ‘stressed out’ (the feeling that if I start to cry I never stop, I feel vulnerable, pain in my belly, light in my head during yoga class). I’ve been here before. I know I better accept the situation as is, but find it hard to deal with the insecurity. From preparing, having high hopes, disappointment, and over again. Not selling the house this month has consequences for our situation. Until now I could find the optimism and trust within me, since the last week I’ve starting to doubt, feel more nervous and not convinced “I will make the sale”.
In the meantime I stick to my yoga, swimming, weight training schedule, eat well, sleep enough hours (although wake up with anxiety).

How can I better define a goal linked with the sale of the house that I can really measure? Like posting every day a pic, video, story. I’m starting to think September 30th the house will be not sold… yet. And then I’ve failed. Or do I choose another goal, and start fresh, like Aimee said, “you’re never behind”.

Any feedback is much appreciated.