Agree with people saying immersion..I stagnated a lot when I was first learning french, for the first 2 years until I started learning this way. I used lingq( sp?) - it does cost for a monthly subscription, although you can use normal books + articles too! It's best to start off with something which has a text + audio - there's a lot of resources online. Assimil is good, bit expensive but, you probably know how to find things online.
Anyway, the way I did it, you get your text + audio. Listen to the audio first. Then, read the text. If it's super long, do it in shorter chunks. When you're reading the text, you underline the bits you don't understand, or phrases that you'd like to remember. Then, look them up and make a flashcard. Lingq does this for you, and there is the free software anki also which is great.
Then, you can listen to your audio again, and see how much more you understand. If you like, it's nice to try and mouth (or talk, if you're not in public!) along with the audio, again it just helps the language sort of ease into your brain. Repeat this until you get bored and move onto something trickier. I went from struggling with 'julie va au restaurant' crap to reading novels in like 4 months, after 2 years of dumbo reading comprehension.
It helps when you do the flashcard for a word, to write down the phrase you read it in. That's cuz its a bit easier to memorise things when you have the context. Also generally, the more sentences you look at at and read, the more the language starts to flow in your brain.. and since you are doing Spanish it helps A LOT with memorising the noun genders, because you always look at the noun and the article together.
eg just a basic dummy example for rabbit - - I'd do something like- le lapin mange une carotte. I could then do a fill in the blanks flashcard with L_ _____ mange une carotte, and that way you wouldn't even have to have any English on your cards.
I wasn't strict with my flash-carding at all tbh - just the making process helps for remembering.. And anki lets you put pictures and stuff on your flashcards.