Hi there, God is Love. Y'all have been going through some pretty rough times.
People with BPD suffer a lot from not knowing how to manage their feelings without hurting others. He sounds like he is full to the brim with pain, anger and lots of frustration at being dependent on you, and just in general at being injured.
I don't know if he was pretty active at all before he was injured and had to have surgeries - if he was abler to move around and now he can't, that is a LOT of reason for anyone to be upset. That does not mean he should take it out on you or anyone, but people often do what they shouldn't, especially when mad. I am assuming he might also be adjusting to being a shut in, if he is unable to care for himself, so he's probably just a big bundle of angry, even if BPD was not part of the equation.
To a much lesser extent, I have had to take on caretaking duties with my husband, as he has been seeing his health decline over the last few years (he's only 40 ) He resents at times having to rely on me to do thigs for him - it insults his independence and his masculinity no matter how caring and kind and mindful of such things I try to be. I have to be careful to not do too much, and to let him do (or encourage him to) do things he CAN do. I do not want to be his mother, and sadly with his BPD I already do a disproportionate amount of things as it is.
How much time can you spend doing things away from him? What tasks do you feel he can't do? Is he in any form of physical therapy? Do you have any home health providers in your area who can assist? Those services are often included in some insurance or are affordable, and the extra help can be worth it. Do you have family close by, or friends, who can come visit and give him interaction with people? Or assist you with tasks? Do you have clergy to whom you can turn if your therapist is not able to comfort and counsel you?
Try to remember just because he tries to put blame on you, you do not have to accept it. He can insult you and be mean, but it does not make those things true. BPD is him projecting his anger onto you, trying to make you the cause of it all because he can't deal with it on his own. Spouses and children are usually the easiest targets, as we have shown we will take it, or have to take it, and won't outright just abandon them, even though that is one thing they all seem to fear.
No, I don't think feeling lost and alone if "normal" for anyone, no matter what stage in life they exist. And now, you're definitely not alone - we're all here with you