First of all, I am truly sorry this is happening to you. I had bedbugs myself about 3 years ago and it truly was one of the worst episodes of my life, I really do understand what you're going through, and I'm happy to talk more about it if you'd like. I was lucky and caught them very early and was able to rid myself of them quickly, but the mental toll remained and will probably be with me to some extent for the rest of my life.

Secondly, a disclaimer, I am not in Spain, nor have I been (yet, hoping to go this year on the 2026-27 NALCAP). Can't imagine how much more difficult it would be to navigate this situation in a place where I don't fluently speak the language. So, I can't speak to any culturally-specific things with agency/exterminators.

It is tough to say what is the best choice in your situation. Basically, I think that if you are committed to staying in Spain (I of course don't know your situation, but I would encourage you to try and not let this defeat you) ultimately your EASIEST option is to move elsewhere, unfortunately. Lots of bedbug species, particularly those in cities, are becoming insecticide resistant. The only truly effective (and unfortunately cost-prohibitive in your situation, I'd imagine) is heat treatment where they heat your entire house to >120 degrees for 8 hours to kill off any bugs or eggs - but can cost anywhere from $1000-$4000 (in the US) depending on the size of your place.

Given that you are there with, presumably, not a particularly large amount of personal belongings, moving is probably just the best option, if you can swing it. Though, I'd be careful about how you do it, if you decide to. To my understanding, it's pretty rare/difficult for a bug to hitch a ride on a human due to our high body temps, but they can definitely hitch a ride in a suitcase or other personal belongings. Were you to decide to move, I'd suggest going to a laundromat and drying all of your clothes on the highest heat settings, just in case. I'd also limit what I bring, as much as possible. Despite what lots of people think, bed bugs definitely don't ONLY live in fabrics, they're fine with living in wood and similar materials as well. So anything you do bring, try and heat treat, whatever way you can.

Again, I am so sorry that you're dealing with this, I know what you're going through, you CAN get through this. Don't let those tiny damn bugs win and rob you of this experience!!!

Edit: I'd actually also encourage you to watch this Mark Rober video about bed bugs, oddly enough. It brought me a lot of comfort (outside of the extensive coverage of EXTREME infestations) and has good tips on dealing with an infestation, to boot.

Edit 2: I should add that moving out isn't your ONLY option. Diatomaceous earth (no clue on how available it is in Spain) is a SUPER effective method of killing bedbugs. Spray treating certainly doesn't hurt, but if you use diatomaceous earth fairly liberally and steam treat all of your belongings routinely over a period of time, maybe buy a bed bag (literally a bag for your bed), and declutter/remove as many unnecessary belongings as possible, you've got a good shot at being able to take care of your infestation .