Afraid of losing day-job by marketing my startup

I'm a level one engineer at a corporate company in Philadelphia, and I've been working on a consumer goods/consumer products brand startup for the past year plus. My market is women athletes for a specific sport. My day job colleagues don't know I've been working on this.

I'm at that point where I need to start marketing it on LinkedIn, Instagram, and writing on Substack, but I'm afraid of my coworkers and people at my company seeing it. As a solopreneur, my story is going to be a big part of my brand identity and marketing, and it will have my face on it. For my day job, I'm remote 2/5 weekdays, and I do my job and do it well, but I wouldn't want any speculation regarding being remote, etc.

Even when launching my product and getting pre-orders, I'd be nowhere near close to replacing my engineering salary. The goal is to ultimately have this or another future venture replace.e my day job. However, to even market pre-orders, I do have to increase my social media presence. Another reason I've been putting off growing social media is that I know social media is a lot of work, and since I'm doing my startup on top of my day job, I have a very limited amount of time. I only try to do tasks that I absolutely have the time for, but I really do need to start marketing and branding at some point soon.

For those of you who know philly, it's a small city. I consider myself introverted but I'm already well known in my religious community, the young founders community here, etc. Everyone knows everyone. So they will find out.

How to stop putting off marketing and branding and get to it, knowing that my coworkers could see it?