Struggling on my internship

STEM degree, first ever internship at a BB (MS/JPM/GS). Long story short, should’ve done more research on the role. Not enjoying it at all. Is it normal that they don’t really train you, just give you work and expect you to figure it out? This style of learning isn’t really working for me, feel like my progress is slow considering I’m spending 2 hours googling ‘what is a lease liability’ and then digging for it in Note 6 of an annual report. 

SSER is pretty tedious, with very lean teams, so often involves spending a whole day not talking to anyone and hardcoding figures into a model. Not to mention everyone else there is way more experienced than I am. Constantly feel like an idiot during presentations and completely fumble the Q&A (even though I always spend ages preparing - just in the moment get really anxious) which stresses me out more. 

Self confidence definitely taken a tumble. Always felt like I was a decently smart person yet at this internship i’m not really able to learn things as quickly. As a non-related degree from a semi-target, I’m feeling especially intimidated by the rest of the cohort. Hours are longer than I thought, and honestly feel pretty stressed at work every day like they're going to find out I don’t know how to do anything. 

Please don’t be harsh, already feeling super demotivated. Anyone with advice on how to make the most of the experience/speed up my progress? Wondering if there’s anyone that felt similar, thanks!