I lost my co-founder, should I look for another one or better go the solo-founder way?

Hi everyone, I'd like to tell shortly my current situation and hopefully you can give me some advise, please :).

I started my startup two years ago, more like a side thing but then I got fired and used the opportunity to go full time on it, managed to do it for a year using unemployment benefits but alone, no co-founder, then I convinced a former colleague of mine to join and he did, and for a couple months we worked together well but his wife got sick and he had to leave to focus on her and their kids, totally understandable.

After that, I convinced a friend of mine who just closed his startup because he couldn't validate his assumptions and we were working together fine. I'm a product guy but also a software engineer so I took the tech responsibility and my co-founder took over product.

Then we convinced another one to join to help us with sales but with him I knew it wasn't going to be very long lived because he said he wanted to tryout but would probably decide when summer was close to be over, so last month he finally said he was leaving.

Since I and my other co-founder were on holidays in completely separated parts of the world we decided to talk about what happened when we get back to the same country ... so we did and he said he also wanted to leave...

Our situations are particular: we are bootstrapping, we have our full time jobs and we have failed to gain traction but mostly because we really couldn't find someone to help us with marketing and sales and since we have our full time jobs there was just not enough time for either of us to take care of more than what we were already.

So now I'm back to square one to the solo-founder stage, and after all of this although I want to have someone who can help me build the company, after these failed attempts to get a cofounder who really can/want to stay I'm not really willing to spend so much effort on it and rather just go the solo-founder way and as much as possible hire people to do marketing tasks and all the other things I can't.

What advise do you have for me?

Thank you!