Assign Data To A Separate Cell Based On Value Of Yet Another

I have a "memo of meeting" excel document used to capture notes during client meetings. In this document there's a cell for "purpose", "agenda", and "notes". The 'consultation type' cell is a drop-down populated by values set in Sheet2. The 'agenda' & 'notes" cells are then populated with information (also stored in Sheet2) based on what drop-down option was chosen in the 'purpose' cell. I'm currently making this happen with basic =IF() statements; however, the problem is that by doing it this way, the =IF() statement must reside in the actual cell which will end up showing the data.

This is undesirable as there may be additional notes, agenda items, etc. that I'll need to add during the meeting and as it's currently setup, I can only have either the pre-populated info OR the ad-hoc notes - not both. It seems a simple fix. Maybe put the =IF() statement in a cell off to the side but have it "assign" the value to 'agenda'/'notes' but that doesn't seem to work.