I feel in a similar way to you with wanting to learn German, I found a few apps on my phone, but the one I really want to use you have to pay to use and it is expensive (well for me because I'm poor). Finding things in German though is probably easier than trying to find things in Celtic languages, but I understand the longing for wanting to learn a language, the feeling of connecting with it. My quote if from a German band (they sing in German amd English) and this band (and another one I like) inspired my to start learning German. I just wish I could find more that teaches you about grammar, and sentence structure as I don't plan on going to Germany anytime soon to actually need to speak the language outloud, I just want to read and write in it and be able to understand music. Well and communicate with a couple German friends in German too. But I do understand how you feel about learning another language. Hopefully you find ways to learn the language you want to.