Oh, I definitely understand depression making it difficult. I used to have a lot of trouble keeping motivated for reading even for things I really enjoyed. What changed it for me was when I started having a long bus ride to and from work, which was an ideal time for me to read and kept me consistent. Maybe audiobooks would help?
As for drawing incorrect conclusions, I think as you learn more about history and political theory, it becomes easier to have confidence in your own understanding. There's no shame in needing help either! I saw some people already suggest companion pieces, which can make the more difficult theory easier to understand. There's also communities here and on Lemmygrad (like !asklemmygrad@lemmygrad.ml or !genzhou@lemmygrad.ml) where you can ask questions about things that confuse you, people are often happy to answer questions for those looking to learn. Something I think that could help too is reading a book written more recently as well, since they tend to use language that is easier for us to understand. A lot of the foundational Marxist works are very old, and personally I'm not sure about any good modern substitutes for them, but I'm sure there's stuff out there. Maybe someone else can chime in with suggestions.
Sorry if this response is overwhelming, I have a hard time judging that kind of thing and this is just something I get a little overzealous about.
I feel this, my friend tends to tell me about stuff they like that I haven't seen/read/played/etc. and is very relaxed about what they consider spoilers. Thankfully our tastes don't overlap much so it's usually not a problem, but occasionally they'll start talking about something I'm interested in and I have to be like, wait please don't lol. I always feel a little bad for it because I'm glad they want to share their interests with me, but I'm so picky about spoilers and if I don't stop them then they will say something I don't want to hear...