I can't judge anyone else, so I will just speak based on what I would want for myself.

I wouldn't want a marriage where I am taking care of someone else who is freeloading off of me and doesn't have any of their own ambitions or goals. Its really important for me to be with someone who is working on going "somewhere", no matter where there may be.

I would want a marriage with a partner who has passion for me and I for him. I wouldn't want to be in an asexual marriage as that sort of arrangement wouldn't meet my needs.

As said already, its up to you to decide what you want out of a marriage. It sounds to me like this isn't enough for you, and I fear that your desires for "more" are just being chalked up to BPD symptoms.

You say that you love him, but were you ever IN love with him?

I'm kind of worried that he is indeed mooching off of you. In any relationship, each partner brings something to the table. If one person works and brings home a paycheck, sometimes the other one stays home and takes care of the house and kids. It sounds like your guy isn't bringing much of anything to the table. I mean he cuts the grass...which is like maybe an hour out of his week for less than half the year? And he sometimes shovels snow? That doesn't seem like he's doing nearly enough. That sounds like the chores that a 15 year old would have!

Also, its not fair to you for him to be living off of your social security check. Of course money is tight while on social security, but as a single person you'd be able to make your check go further if you didn't have to pay for all of his stuff, too, right? So in this sense it sounds like he's the one who is holding you back.