The only boundary we have in place is that I won't lend him money under any circumstances. We had a b/u triggered by him testing that boundary. The other boundary I tried to put in place was around how frequently I would respond to his texts. Him trying to breach that boundary caused our last b/u. Boundary setting and busting seem to be a big issue for us. We did both share things that we each do that make us happy or sad, but they aren't really boundaries, more suggestions. I don't know what boundaries I need to set or even how to go about it. So far, it seems that when I assert my needs, everything goes wrong.
Sounds like you are on a good track. Consistency is critical with boundaries so stick to them. The first ones are being tested and blowups are expected. These are just normal extinction bursts which tend to get smaller over time.
Financial boundary makes very much sense and is an excellent move

. The frequency boundary is also very, very valuable as it decreases his sense of control of you and it increase your peace of mind. Remember this takes time and when he is calmer he should get that some boundaries/protection/privacy is healthy - and if he is not then that is his problem, no need to make excuses.