Casual Conversation

The "accent" is completely normal; every language we know changes a wee bit how we use all the other languages. Even the native ones¹. Linguists call it "language transfer", or "linguistic interference".

Do you get an accent if you don’t use a language often then try to talk in it again? Is that even a thing?

I think it's the opposite: your Cantonese is interfering on your English more, not because you've been using English less, but because you've been using Cantonese more. If for some reason people in your home decided to speak something else among yourselves, you'd get that Cantonese interference being slowly replaced with interference from the new language.

I fucking hate my voice… // Do y’all like your voice?

No, I bloody hate my own recorded voice too. The pitch feels really off.

I think it's fairly normal to hate it though. It's not just the mismatch between hearing it "through the skull" vs. "from the outside", but also because our own internal "abstraction" interferes on it.

For example. Let's say you're saying "wug"² /wʌg/. Then you record it, and you realise you aren't really pronouncing it as [wɐg], it's more like [wəɣ] or [ʋɐg] or even [ɰʌ:]. Everyone was hearing you pronounce it a bit slurred, but you don't notice it yourself because inside your head it's crystal clear.

If this worries you, don't — it's like this for every single body out there.

1. Anecdote time: people sometimes ask me where I'm from, in the city my family has been living for four gens, because my Portuguese got some "accent". This bugged me for some time, so I investigated it further and... to keep it short, it's a bunch of phonetic features from my second language, Italian. That I started learning when I was, like, 8yo? 10yo? It's fairly subtle though, non-Southerners are quick to point out my thick Southern accent, it's only other Southerners who ask me where I'm from.
2. "Wug" is a nonsense word. I'm just using it for the example.