Gracias, Harold! Vas a hablar Español pronto. ;)
I learned Spanish as an adult and agree with your advice. Immersion is essential! I eventually dreamt in Spanish but spoke no English for months and lived with a family in a rural area.
I made the same mistake as you; English was the gatekeeper. Spanish grammar isn't structured like English (obvio). So, I restructured English grammar to match Spanish to train my brain, which helped with sentence structures.
We never stop learning new vocab in our native language, and Spanish words that I learned before the English equivalent remain the primary (go-to) word that pops into my head when speaking English. It's bizarre!
Learning a foreign language as an adult is among the most rewarding achievements. You have to work hard, and there is no instant gratification. It's the best!