When adding new company record, don't you want to populate Business, Category, Subcategory, etc? Why would this be optional? I suspect this is contributing to issue because combobox RowSource has filter criteria dependent on Bill_ID but your code does not populate this field.
If contact cannot be added without associated company record, why use DLookup to find company name - isn't it already available in Company combobox? Might want code that prevents selecting/entering contact without company first selected/entered.
Saving category in tblJournal is duplication of data because associated Category can be retrieved via tblSubcategories. Appears to be circular relationship. Similar for Bill_ID field - this can be retrieved through tblCompanies.
I NEVER use multi-value field and avoid attachment field (a type of multi-value field). Embedding files in db uses up Access 2GB size limit.
Also advise not to use spaces nor punctuation/special characters (underscore only exception) in naming convention: better would be IsNew, IsArchived, FollowUpDate. Also advise not to use reserved words such as Date as field names. Better would be DateEnterJnl.
ArchiveDate is more informative then just a yes/no field. What significance is New? field - how long is something 'new'?
I find lookups in table more annoying than useful, especially when an alias is involved.
Save yourself some typing. Value is default property for fields and data controls so don't need to explicitly reference.