Living in Spain at the age of 19 with no college degree, no matter how sharp your skills are, is truly a pain in the ass.
It sounds like your parents were able to support you, did you never consider to move back with them then figure out your job prospects in the UK? I'm just imagining you're the son of one of the many British expats that live on the Canary Islands/Andalusian/Valencia coast. There aren't many tech jobs around there but I saw a few companies started by people in these typical expat areas that might be willing to take people like you (given you like Spain enough to stay in).
Did you ever consider to stay with your family in Spain and try to get a college degree in there? In any case, glad to see it's working out so far. The best thing when you're in a hole is there's a lot of room for improvement.
Before I reply, I will give some back story: I lived with my mother and sister in the UK and wasn't working, my skills with the Spanish language were poor to say the least and finding a job was proving near impossible.
I moved back to the UK to widen my prospects and it worked to be honest, even without a college degree I managed to find work, I did look in Spain, don't get me wrong, but there was nothing which resonated with me and I became disillusioned with the country and the idea of living there.
I did consider moving back to live with my mother, but the harder my situation became, the more focused I became on succeeding, if I moved back I would have given up a big part of me, my drive and passion for my work and my love for my girlfriend, there was no tangential course which I could myself being willing to give those up.
As for your last statement, I couldn't agree more, the lower you sink, the more scope there is for climbing. Every time I get kicked down, I feel more empowered, safe in the knowledge that I've been through worse things and I always found a way to make them better.
Of course, I couldn't have done it without the support of my friends or girlfriend, I can't thank them enough for the help I've had.
I moved back to the UK after spending 3 years in Gibraltar, my girlfriend who lived across the border in Spain followed me. Places like Spain is where people go when they've already made it (or run away to when they've made it illegaly), it rarely the place where you make it. I found it easy to get work in London, apart from work being abundant here I also genuinely know how to work the jobs market here, and hence helped my girlfriend to land work quickly. I keep moving back to London because the exposure to culture and work experience here is second to none. However, it's a tough place. Very unforgiving, and everything apart from culture and work is a lot harder to deal with here. It was the third time I moved here and by this time I had the right connections to have somewhere reasonable to stay. Very much unlike my first time, so I can relate.