I have the same combo of illnesses (though maybe less intense Alexithymia)

A useful resource for me is an emotion wheel (you can find one with your favourite search engine)

It has tiers to it, so you could start with happy, for example, then get more specific with the sub-categories

You and I both know there would be great difficulty in identifying what actual emotion you feel with regards to your childhood home, even with an emotion wheel. Since you’re not being judged on the accuracy on the emotions identified, you can pick a few that sounds reasonable.

For me, your assignment would more feel like a language exercise of picking the right word that makes sense in context, rather than thinking about the actual emotions experienced. In this case, the emotion wheel would help by acting as a reference of emotions to consider, and act as a sanity check if you’re writing something positive but chose an emotion that is a sub category of anger, for example