One thing about what you wrote jumped out at me. You say "I love building and working - always have, always will." and "I'm forever building my own side projects as I love it." But then later you say "I can't bare the devs that go out of their way to work weekends without being asked." When I work weekends without being asked it's usually because I WANT to. It's because I'm having fun. So that strikes me as an odd thing to say as a part of why you can't bear it.
Now I am keenly aware that there are plenty of workplaces where this isn't the case. Where employees get their life force sucked out by perpetually unreasonable deadlines, expectations of long hours, etc. I've been in those situations. They're miserable. You say you're in a great job. But then you go on to describe something pretty unpleasant. My recommendation would be to engage in a job search for a better environment while you're securely employed at this place. Take your time. Don't be in a rush. You might want to consider branching out to a completely different segment of the industry. Some domains in the software world (things like games and finance are the big ones that come to mind) have a well known reputation for demanding long hours and sucking the life out of you. You should probably make a conscious effort to avoid those. When you're interviewing, ask questions specifically with the goal of figuring out what kind of a culture they have. Use indirect questions that don't make it obvious what kind of answers you're looking for. It's a sellers' market right now. Good engineers are hard to find. It's a good time to be looking.
You might also want to filter the places you interview according to the type of atmosphere you're looking for. I've been in fun healthy workplaces that were pretty high pressure. This could be because it's a small startup company with limited runway that has to deliver or die. This could also be because you're doing things that are inherently high consequence such as, say, a space shuttle launch or ER doctor (to use a non-software example). I've also been in fun healthy workplaces that were pretty low pressure. Research-y work is ofter like this in my experience and it can be at both large and small companies.
There are people who love their jobs and have healthy work environments in both high pressure and low pressure workplaces. So I'd recommend thinking carefully about what kind of an environment you're looking for before you start interviewing and use those characteristics to choose where you're going to look.
The outcome of working weekends on my own project is the chance that I may actually build something that can feed my children, give them a good life, give us freedom etc.
The outcome of me working weekends for a company I work for is potentially having a pat on the back from my project manager and to have my name on a powerpoint at the end of the a sprint if I'm lucky.
The CEO doesn't even know your name. Know-your-worth.
Now I am keenly aware that there are plenty of workplaces where this isn't the case. Where employees get their life force sucked out by perpetually unreasonable deadlines, expectations of long hours, etc. I've been in those situations. They're miserable. You say you're in a great job. But then you go on to describe something pretty unpleasant. My recommendation would be to engage in a job search for a better environment while you're securely employed at this place. Take your time. Don't be in a rush. You might want to consider branching out to a completely different segment of the industry. Some domains in the software world (things like games and finance are the big ones that come to mind) have a well known reputation for demanding long hours and sucking the life out of you. You should probably make a conscious effort to avoid those. When you're interviewing, ask questions specifically with the goal of figuring out what kind of a culture they have. Use indirect questions that don't make it obvious what kind of answers you're looking for. It's a sellers' market right now. Good engineers are hard to find. It's a good time to be looking.
You might also want to filter the places you interview according to the type of atmosphere you're looking for. I've been in fun healthy workplaces that were pretty high pressure. This could be because it's a small startup company with limited runway that has to deliver or die. This could also be because you're doing things that are inherently high consequence such as, say, a space shuttle launch or ER doctor (to use a non-software example). I've also been in fun healthy workplaces that were pretty low pressure. Research-y work is ofter like this in my experience and it can be at both large and small companies.
There are people who love their jobs and have healthy work environments in both high pressure and low pressure workplaces. So I'd recommend thinking carefully about what kind of an environment you're looking for before you start interviewing and use those characteristics to choose where you're going to look.