how do i restore and increase fluency in my native language?

long story short, spanish was my first language but i moved to the US when i was five.

my parents and i have always spoken spanish (or spanglish sometimes lol) at home, and we would go back to our native country once a year at the beginning of our time here. that tapered down as time passed. now my family’s moved back to our native country, so i’ll be going to see them more often. my parents are obviously using less english now, and our native country is becoming a larger part of my life than it was growing up.

i’m an adult, and i want to be able to speak at the level of other adults in my home country. i want to be able to fully express myself in spanish the way i do in english, but i feel extremely limited. it’s not like i can’t keep up with the conversation mentally, i understand 99% of the things being said. but when i speak, i find myself hesitating, stumbling over words and using english to fill in the gaps. my cousins have told me that i developed a light accent, but my parents don’t notice it.

when i crack open classic pieces of literature, it takes me ages to get through a single page and really understand it.

i find myself defaulting to a limited set of phrases, i use certain words over and over, and i feel like i’m behind culturally as well. since most of the conversations i’ve had in spanish have been with my parents, i’m not caught up with slang, cursing or “young” vernacular. (side note: i’m gay, so i’m also not caught up with gay culture at ALL)

i’d appreciate any and all advice. i just want to connect with others in spanish the way i do in english. i’m proud of my heritage, i love my home country, and i want to feel like a part of it all.

tldr: after living in the US my whole life, i want to reconnect with my native language and express myself without limitation. any and all advice is welcome.