I have a startup idea and I have almost developed everything myself, from the Business Plan to the actual App and customer base via social media communication.

Fortunately it is a business niche which can have an easy go to market without any R&D or particular expenses on testing and there are already some customers registered on the website to try the beta, once it is out.

I have previously tested the idea with a MVP and had some revenues.

Now, my question is, considered I don't have funds to invest (I'm mainly doing everything myself/within the team), do I really need an investor or an accelerator to back me up during the service launch?

Additional info:

The idea is to offer a B2C service for geolocalised car washings using waterless products and delivering quick and professional results at a reasonable price. A definite competitor (at the moment only in the US) advantage is the partnership with a car detergent retailer whose products can offer a professional result without having to bring a lot of equipment. And, apart from that, we use a custom proprietary matching algorithm.