hi SpaghettiSandwich and

what a relief it must be to finally identify what youre experiencing, and to learn there are strategies to deal with it and to cope. things really can get better, and im glad you found us; youre among folks who get it, and have walked, or are walking in similar shoes.
additionally, we have lessons and tools to the right of the board that can make a huge difference, and give you a lot more breathing room. some of them can be awkward at first; my advice would be to practice them with everyone in your life. they work with everyone, people with BPD just tend to need a higher dose of them.
He tells me that 'dealing' with my emotions is too much for him. I'm left feeling alone and uncared for no matter how much I give.
i really hear you on this. it can be a very isolating feeling.
for starters, its good that there are times where you can speak your mind and your heart, and it helps that he is honest with you about his limitations.
this is going to seem very trite in comparison, but i want to share a brief story about the limitations of one of my friends, that frustrated and hurt me. im very close with most of my friends. we can speak our hearts and minds pretty openly, and we tend to be pretty supportive of each other. i had one friend, though, who could make you just feel awful if you tried to cry on his shoulder, so to speak. he would always say the wrong thing. id get frustrated and resentful. id try to explain to him what was wrong with his approach.
eventually, something clicked. there was a lot i enjoyed about our friendship. he was hilarious, fun, and the two of us could laugh about anything. so long story short, i accepted his limitation, that he simply was not an ideal shoulder to cry on, and focused more on the things about our friendship that i enjoyed. if i needed a shoulder to cry on, i went to someone that was good at that. if i needed a laugh, i went to him.
obviously, he wasnt my girlfriend, and friendships can be very different, but it still illustrated to me that basically, some people are better or worse at some things than others. it pains me to say it, but i know there are times when people could have used support from me that i couldnt give. it is common for people with BPD to struggle with this. often times, for example, they may take any dissatisfaction in your life as a reflection of them, or a complaint against them, or feel inferior for not being better able to help.
now im not telling you to simply accept that you cant share your emotions with him, i dont think that need be the case; just that there are times he will be better at it, and times that he wont. having a strong support system in place is crucial for these challenging relationships, so it will help to have a diverse group (us included!) who you can open to.
can you tell us more about your needs, and how he responds when youre trying to open up?
how long have the two of you been together, and is he considering therapy since hes open to the idea that he has BPD?