What do you mean by "I take care of my mom"? Are you helping her out financially, helping around the house, etc., but she is physically independent? Or, is she physically dependent upon you for activities of daily living? Either way, I commend you for being that sort of person in her life. However, as you already know, this could be a deal-breaker for any potential partner. "I can't do this/that because I have to be there for my mom." is not going to be received well.
Now, having said that, and I am just imagining a situation where this might work, perhaps it might be that a female partner, who might have children and a career, needs a person in the home to be a father and mentor to her children, take care of the home, do the bills, transport the kids, etc. She might be looking for someone she can trust implicitly to be that responsible, reliable person. Marriage is a partnership. It's a 1+1=3 equation where both benefit for an additive effect. It's not about you, it's not about the other person, but rather "us". Being a stay-at-home father is not uncommon these days, nor is working from home. If you had your own home nearby to your mother (within a mile, or so), so that you can check in on her frequently/daily, that might be a workable solution.
I know that in some cultures, there may be up to 3 generations of family members under the same roof and they make it all work. It's just not something most of us in the US are used to dealing with. My parents did the same with their parents when they became elderly, that is, after they put on an addition to their home and made an independent living space for them. Most people are not able to do this though.
I can feel your concerns here, as your situation does narrow down the "playing field". However, working at a busy, metropolitan hospital for nearly 40 years, seeing the 100s of thousands of people over the years, I have seen all sorts of life partners making it all work, whatever the situation.
