Life is full of tradeoffs, but it sounds like you're doing the right things. They'll understand and appreciate what you've done for them someday.

Don't feel guilty for taking government assistance. The system is rigged HARD in favor of the wealthy, and robs us all blind for their sake. If you can take back some of that to help you and your kids, by all means do it, and don't feel bad about it. That said, a good career, and the stability and security that come with it, will likely be better for all of you in the long run. If you're still in a position to, my advice would be to take the assistance for the time you need, to be there for your kids, but don't overdo it, and pursue the career once you feel you and your kids can handle the time apart it will entail. If you've already done that, that's okay too, just strive for a healthy balance between work and family. Don't beat yourself up for not being perfect, nobody is, just do your best. My condolences on losing your husband.

There are no solutions, only tradeoffs.

never feel guilty for taking assistance. there's lots of people who don't need it and aren't citizens who get it. And you'll never win as a parent you'll always feel guilty for something just enjoy the moments and create those core memories your kids will appreciate how hard you worked in the future

Don't feel bad for using the safety net, that's what it's for. Now you're back on your own two feet you should instead feel proud that you're providing for your children and their future.