This is an area where Welsh is slightly different to English…
…when reporting speech or an idea which would have been in the present tense at the time, ‘bod’ is used for that, and the present tense is used to express that idea (as it would have been at the time).
English prefers to relay the whole thing in the past tense by contrast.
This seems very odd at first but quickly seems completely natural!
Luckily SSIW is great at running you through these things until they ‘feel right’…and has quite a focus on ‘that’ which is quite a pivotal word for building longer sentences with different parts.
You are going through the same ‘hang on a second’ type of questions that I did - it is an on-the-button type of question - which is a great sign.