Help with choosing a new language
I'll try to be brief. I am fluent in English and Spanish. Spanish is my first language, but I have been moving back and forward between Mexico and the U.S. that is now hard to say which language I know the most. For practical purposes I would say that it is easier for me to speak Spanish, while reading and writing is easier for me in English. I will graduate from medicine, so science is a big deal for me. When I graduate from medical school I might be fortunate enough to study for a couple of months in Europe.
My options are German, French, and Italian. What is most important to me is its usefulness.
Italian for me sounds beautiful and is the fun and easy approach, but it somehow lacks usefulness.
German because there are some original works which I would love to read. The language attracts me since Germans helped shape many sciences. I also love the countries that have it listed as their official language.
I am considering French since it is spoken in more countries. In addition, Doctors Without Borders seems to favor those who speak French and working for them is in my bucket list (obviously in distant future).
To this day, German remains one of the most useful languages in many scientific fields, including medicine. It is also one of the most important languages in academics, with about one tenth of all books being published in German. Undoubtedly, for straight usefulness, German is the way to go.
However, if you decide that what you're really looking for is a language with a rich history, that is fun, and is only so challenging as to keep learning engaging long term, then you should probably go with German.
Here's a great introductory video into the German language: https://www.youtube.com/watch?v=K3IImGiiY1Q
for raw usefulness, i would go with German. German also has the bonus of being quite similar to other languages around it giving you a leg up if you ever wanted to learn Swedish for example. also i think it is admirable that you want to work DWB.
I think German is a very good choice. What I would say about Italian is that while it lacks usefulness on the Global stage, it doesn't lack usefulness within the Eurozone itself, where it has the third largest economy.
It really depends what you want to do. To read German texts, German is obviously very useful, but as far as speaking goes, most Germans speak nearly fluent English making knowledge of German somewhat superfluous for basic interactions. French & Italian are different in this regard.
Given that you already speak Spanish, Italian will be easy to learn.
Italian and Spanish have a lexical similarity of about 85%, consider that German & English are 50%. If you're thinking about the greatest utility-per-hour-spent studying Italian would probably rise to the top, but it does have more global limitations that French and German, there's no doubt about that.
French would be a nice balance between the benefits you'd get from Italian and German, but then of course, you'd have to deal with the french. Good luck choosing!