Boundaries

My fortnightly task with my counsellor this time is to think about boundaries, particularly, having boundaries between me and other people and deciding where they lie.
I think there are two types of boundaries. There's boundaries I set withing myself, and boundaries I enforce externally. At the moment, I'd consider myself fairly "good", if that's the word, at setting internal boundaries, for example, my "robot mode"" is like an unhealthy expression of it, where I refuse both to let the outside in, and the inside out, on an emotional/psychological level. Healthy boundaries are harder to do, being specific about things, creating more than one rule, it's more complex. I would say, consciously, that I'm not a big 'black and white' thinker, in that I don't like to set lines and be firm about crossing them, but I think that there is a shadow side of it that is quite black/white sort of 'splitting' thing. All about me vs the rest of the world and what's allowed for me compared to what's allowed for the rest of the world.
I wouldn't call myself a very unconstrained, boundary-free person in the past, but I'm getting to be now. What used to be a big issue for me was all these internalised (such that I thought they were my own) rules about what to say and do, and  how to see others, pretty much based around the idea that I have to be different to how I am, careful, or else people won't like me. And that people (everyone) liking me was really important, and how I felt about them was unimportant. That not liking someone meant I'm bad or judgemental, but if they didn't like me, that was my fault too. So I had a lot of internal boundaries in terms of constraints on my behaviour and outward appearance, but very low internal boundaries going the other way, in that I was very unresilient to criticism. At the same time though, I believe that I had a strong view of 'the line' in terms of not letting myself be treated in such a way to lose my self-respect, but looking back, I'm not sure. Those closest to me, especially my family, were crossing that line and hurting me regularly.
In terms of integrating all this and looking at the present day, it seems like there are at least two things I want to work on:
1) boundaries as in what I will and will not tolerate from others, and how or when I would let them know, if I want to, what they are or if the person has crossed them
2) boundaries in terms of how I relate to others, especially to do with not getting pulled in to other people's problems to the extent that it's unhelpful to them or me.
My support group program for the problem I was having last week about this was "Let go and let God". I don't believe in God, but I think the universal message is to leave things up to others, or to time. Not to intervene. Is a huge challenge for me not to do that, out of a need to help people which is driven by my difficulties accepting that 'problems exist' with any peace of mind at all, as out of any kind of altruism. It's out of selfish motives that I help people, my friend Mike thinks that that's why anyone does. I argued with him for a long time but now I think I can accept that. It really does come down to an idea of 'selfish always being a bad thing' that I've been stuck on. To treat yourself well too, to make your needs important to you, maybe is "selfish" but it's useful and that's important.