Search Results: lost and confused

Hi there. :)

So, my best friend is going through a bit of a rough spot. She has a super sweet boyfriend, and this is his first girlfriend. (We're all about 20 years old.) My friend (we'll call her Joyce) tells me all sorts of things about her life and little things about her realtionship that only besties tell each other, and I'm glad I have her confidence and I never want to lose her trust. However, I'm in an awkward spot because her boyfriend texted me yesterday a long email about Joyce, where he talked about how distressed he was that she was in a bad spot and how much he wanted to help, and for me to give advice. I don't really know her mans that well, and my ego is stoked he came to me for advice (though it makes sense, since he knows I probably know her best)
I don't want to be a snake, and I tend to turn into one when Im between girlfriend and boyfriend and giving them both advice (this has happened before lol and it turned on me pretty quick, and I don't blame either of them) Anyways, I don't want that to happen again. But I'm in a tough spot. Best friends before besties baes though... why am I so confused? Here are my options:
1. Tell him things my best friend has told me in confidence that he probably has a right to know but I don't have a right to share
2. Tell Joyce he texted me, show her his texts and say 'see, those things you thought about him were wrong, he really wants to help!" and she can help me formulate a reply to him.
3. Give him a generic response with generic advice
4. pretend I didn't get the long email.

I've been talking to this shy-overthinking guy for a few months. It's pretty clear we liked each other. Due to some differences and his doubts about me, I initiated to stop pursuing to be together. But he said he would always be there if I needed him until one of us finds a partner. After that, our interaction remained the same, as if nothing happened. That lasted for 2 weeks. We even planned for a staycation a month or 2 from now.

Then, his responses started getting bland and he ignored me being affectionate and just responded my text but rarely asked questions. That lasted for a few days, then he seemed to be interested again though he still didn't ask as many questions as he used to. But because he is so confusing, I decided to give him bland responses as well, but still joke around sometimes, but no rimantic emotions involved. Though I am actually still interested in him but my pride is keeping me from making more efforts because I feel doubted and rejected. What is wrong with him? Is he still interested? Or just doesn't wanna lose my attention? Did he change his mind and wants to be pure friend? What should I do?