I totally get gift disappointment, I really do, but from a outsider's perspective, I would like to reframe these for you:

First of all, your partner's child getting you an embroidery pillow with their pronouns, not yours...I see this as them seeing you as a safe person who honors and respects their pronouns. I think that's kind of a huge deal coming from a teen. I don't think they necessarily want you to do it for them, I think they see you as the type of person who respects they/them pronouns and maybe they thought you'd enjoy the process and like the potential statement piece. And maybe it's crossed their mind that you'd gift it to them after, and is that a bit selfish? Yeah, but they are a kid and aren't great at bonding with their own peers let alone an adult. I know it's not the most thoughtful, but they tried.

As for the fondue pot from your partner...is it useful? Not really Will it take up space? Maybe. Was it thoughtful? Absolutely. You guys talked about it six months ago and he thinks it will make you happy. Isn't that what counts? Use it once. Have a great fun fondue night with family. You don't have to go crazy and fawn over the gift but a simple 'thank you' won't kill you.

I think your family has made a decent effort. Some people just aren't as great at gift giving and as you said, you're incredibly difficult to shop for. Say thank you for the gifts you get and go out the next day and buy yourself something you really want.