To add, if your partner thinks you're being lazy by not having huge ambitions, they have a lot to learn about being disabled. Why should we put ourselves through hell to "better ourselves" when we're content with who we are? Ambition can cause a lot of suffering for someone who has different struggles. They need to learn that sometime with disabilities has worked harder than most realize to come as far as they have. I'm sure you've been in a worse spot in life before being able to manage living with a disability. Tell them that. You've already achieved your biggest goal. Surviving the challenge of living with a disability. You've overcome things most people haven't. Those things can be extremely difficult and some people can't realize that. If they want you to have future goals to "better yourself" instead of just being happy with you, they have a problem. You are successful. You have what you want in life and aren't miserable trying to reach a goal that will cause you more stress and pain. This person needs to learn that they have to compromise in a relationship. If can't be with someone because they don't meet all the "criteria" they set, they have some growing up to do and they need to learn more about being disabled. To me, most people that want others to "better themselves" or they won't stay, they're people who want to show off the person they're with. They want to go to their friends and say, "Look, my girlfriend wants to be a fashion designer and she's in college right now studying." Because that makes them look like they have such a prize for a significant other. That's unfair. You don't have to be a show pony to make them look good. This person should care for you AS YOU ARE, or else over time they'll make you feel like you're not good enough when YOU ARE. You're amazing as you are and I'm proud of you for being comfortable in life. I'm not comfortable, I wish I could be content.
My last point is that if you have no goals right now, they need to be a little flexible. You may have just tackled an extremely difficult phase in life and aren't ready to tackle the next. They should support that. Life is long. But it is also short. I don't believe in "seize the day." You don't have to be constantly growing. Even children have growth spurts. There are breaks in between. You cannot be rushed to grow. You need to grow on your own terms. And in a relationship, you grow together. Not expect someone to change because that's what you want them to do. And saying you can't be with someone just because they don't want what you want them to do is wrong.