Confounding to learning language, on top of one's base ability to do do in general, are the teaching methods not meshing at all with the individual. For me, rote memorization of anything is nearly impossible, doubly so if the thing to be memorized has no immediate utility. "Conversational" language learning and similar that give you a bunch of vocabulary and bring in the grammar later are why I failed Spanish 1 three times. I need the grammar first, then words with etymology. It also helps to not fight with phonetic collisions between different languages using their own bastardization of Latin script, which is why I was far more easily able to meet my college language requirement by teaching myself classical Greek and translating the things I thought were interesting.
This is fascinating to me, because I am adamant that learning grammar (and especially verb conjugation) is completely counter productive when starting to learn a language. Especially with Spanish, where every tense and person has different terminations.
I literally just ignored conjugation and spoke in infinitive for a while.
Yo comer pan. Tu comer pan. Ayer/mañana el comer pan. Etc...
Likewise not worrying about gender, articles etc. If you use the wrong el/la/lo/les/whatever, it almost never matters, whatsoever.
Likewise if you put words in the wrong order.
Everyone understands it all.
So, just focus on building vocab, fluidity and confidence. The tenses come in time.
I do agree, though, that etymology - or at least noticing similarities between languages - can be very useful. Spanish and English speakers already know thousands of words in each language just with some basic rules. -al is the same (metal). -tion becomes -cion (conversation, conversación). Etc...
I suspect that your struggles was that you were being evaluated on the wrong things...
I'd be curious to hear your experience and what you think of what I've said.