I can help
Can you take a look at the following link and answer the questions at the bottom of the sheet? Your answers will allow me to accurately model the loading and size your beam. Thanks
Sorry for the delay, I have been traveling the last couple of days.
Item #1, you said New Beam #4, then later you said the new header would only support the roof/attic. That sounds like a New Beam #3. Can you look at my sketch again to be sure?
Item #2 you gave me the spacing of your joists/rafters, I need to know the span length of those members (distance between supporting walls).
Let me know when you come back online.