Hey,
I find it helpful to not only read in the language you want to learn, but also try to think thoughts in it and to formulate those out to yourself. Talking aloud to oneself might be a bit odd sometimes, but it is helpfull, because you not only have to pronounce the words correctly, but you also have to create right sounding sentences for yourself... and not only read the sentences, that are already formulated by someone else.
Also it helps to find people online, that communicate in the language...maybe theres also a spanish Star trek Board somewhere

, then you can post there. You can think your posts while writing also loud...or you look up a chat with spanish people.... you also could open a thread here looking for a tandem partner and then you post in that thread in spanish..or sisnt that aloud? Well but I guess when its only a one thread and its in the subject line, what the threads for, it should be all right really.
What I find the most scary is talking English with German people. I find it easier to talk english with native speakers...so maybe when you wanna talk spanish again you can find native speakers, who when possible, should not be proficient english speaker, cause, for me at least, when I know that the other can speak my native language and we could communicate way easier in our own language but use a different one, it feels strange and uncomfortable.
Oh and try to write a story in Spanish for example. With dialoge. Can be something easy and short, but let the characters converse in spanish. That trains too. However not sure if it would work with your cardies, cause they are probbaly used to to speak english in your mind..sort of.
I for example could not write them in german, and even my english is not proficient at all, I would try to write them in english, cause I only watch DS9 in English, so they talk English in my mind and certainly not german.
But maybe it does work for you or you just take a character that has no strict language in your mind yet.
Others than that I guess it really is just jumping over the shadow. And keep in mind most native speakers are always impressed when a non native speakers speaks their language no matter how stammered and wrong it sounds. Someone can speak the most broken german to me and I still find it great in a way, because the someone tries.
And when i talk English with friends who are english natives they always find my english SO perfect...while I know its not, but they are just happy I try to communicate with them as best as I can.
So remember when wanting to speak spanish that no one is to harm you, when you speak it wrong, but people will be happy that you try at all.
TerokNor