Partner is starting HRT and I'm very nervous

My boyfriend just had his first T shot and I'm stressed about what's to come. I have very few role models in real life of pre-transition relationships with FTMs that survived transition. Besides the social logistics of coming out again in all my spaces, the daunting future of appearing to be a het couple, and having to explain his transition to the cis/het people in my life, I am concerned about biological changes that may be unnavigable. If you have experience with any of the following concerns in FTM relationships, I'm open to advice.

Libido changes- I'm cis but I've been on spironolactone for two years due to my own crazy hormone shit and I'm seeing a lull in my own libido that I've never experienced. I've read a lot on trans boards that folks experience changes in their own sexual attraction/orientation in general. I'm worried that I won't be able to please him anymore or that he eventually won't be attracted to me.

Aggression- One of my favorite things about my boyfriend is that he is thoughtful and gentle. I was abused and manipulated in the past by a ftm partner in early HRT and it's made me way more sensitive and put me on high alert. I know that much of that was not attributable to HRT, but I really don't know how not to be scared that it will happen again.

Besides physical aggression and libido, I've heard a lot about "man brain" and I really don't want to lose my kind and considerate partner. I think at the core of this, I am worried about losing who he is due to biological changes. I'd be lying if I said I wasn't looking for some kind of reaffirmation that this doesn't have to be the case.