Trying to find a balance-What help looks like

[BPDGen2]

Hello~ I'm hoping to glean some advice from folks who have walked this road and what they've learned along the way. Like most people here, the backstory is heartbreaking, complicated and exhausting. My (adult) older sibling has had a multitude of medical and psychological challenges (BPD, depression, PTSD) that have upended our family and positioned me in a care-taking role since we were pre-teens. It has been a rocky relationship, but there is genuine love for each other and an appreciation of each other's goodness. That helps me find empathy and endurance during drama-laden times. At various points in our adult lives, I have been guardian for his children (3) when he was not in a place to care for them properly (Their mom was deemed, rightfully unfit by authorities and is basically out of the picture).

Most recently, I was a long time guardian for his son (DN), who is now 19 and has disorganized attachment and an emerging BPD. Behaviors have ramped up significantly since DN has entered adulthood, becoming more intense, disruptive and dangerous. He's in therapy (so am I). My relationship with him at the moment is beyond exhausting, I suspect because it is also one big, daily, trigger of what I navigated with his dad (Dad has gotten better with age- but far from independent or stable)... .so now I feel like round-2, here we go again.

In my interactions, I don't want to be insensitive but I find myself very protective. I'm not wanting to project outcomes, but the manipulation/boundary pushing behavior is SO familiar my patience is perhaps less understanding than it was 25 years ago. I have managed to get my life into a stable, joyful place that DN has rejected (or has sabotaged his involvement in) at every turn. He does not have much support locally beyond myself and my SO (who is supportive but understandably exhausted by the intensity of DNs needs). I'm at a loss. I want to support DN, while also protecting my fiancé and his kiddos from the craziness that can accompany BPD.

Through amazing counsellors I have managed to maintain some semblance of functionality in my own life, but it is not without sacrifice. When DN is "Booming" like he is now, it impacts my work (missed 2 days attending to suicidal concerns) friendships (missed important event for friend, missed getting together with others, one close friend is now avoiding contact, I think because too painful to watch... .)
So my questions:
Where best to turn (sibling or parent forum) My situation is wrapped around both.
What do healthy boundaries look like for a young-adult of his age?
Any advice on multi-generational aspect?

Even though rationally I know my Brother is not responsible, I feel that old tinge of his manipulation through the disfunction of his kiddo, who has inherited dad's talent for pushing my buttons and all boundaries I set. It's been a rough couple of weeks and I think DN and I are laying the limits (ground-rules) for the relationship between us as he becomes an adult.

Any thoughts, advice and encouragement are truly appreciated. Feeling guilty for having limits. 

Our objective is to better understand the struggles our child faces and to learn the skills to improve our relationship and provide a supportive environment and also improve on our own emotional responses, attitudes and effectiveness as a family leaders

[Naughty Nibbler]

Welcome BPDGen2:    

My goodness you have had your hands full. I heard a quote today indicate, "Life is a series of problems for us to figure out".  My goodness, you qualify as an  

So my questions:
1. Where best to turn (sibling or parent forum) My situation is wrapped around both.
2. What do healthy boundaries look like for a young-adult of his age?
3. Any advice on multi-generational aspect?

1.  You can learn about boundaries and communication skills on both boards.  Since, your biggest concern is in regard to a parenting situation with your nephew, I'm thinking that the Parenting Board is a good place to move this post to.  I'm thinking you can post on both boards.  When you want to zero in on issues with your brother, and want the perspective of others with sibling problems, then you can post certain questions/issues on that board.  

2.  What are some of the issues around which you want to set boundaries for your nephew?  (i.e. what are some of the current problem behaviors and issues)

3.  I'm thinking that the boundaries and skills used might be similar for both of them.  The specific boundaries might differ between you nephew and your brother.  One communication skill might prove better for one versus the other.

Even though rationally I know my Brother is not responsible, I feel that old tinge of his manipulation through the disfunction of his kiddo, who has inherited dad's talent for pushing my buttons and all boundaries I set. It's been a rough couple of weeks and I think DN and I are laying the limits (ground-rules) for the relationship between us as he becomes an adult.

 The important thing to remember in regard to boundaries is that they are for you and you are the one who needs to consistently enforce them.  They will be tested and they won't be liked.  If you aren't consistent in enforcement, then they will either be less effective or not effective at all.

We look forward to hearing more of your story.