Extract and Sum Numerical Values using string matching from single/multi value cell

I'm trying to create a schedule and want to be able to show both (Workers x days) but also an overview of each project and what actions are occuring on what day. I need to be able to sum all allocated time to have knowledge of total time alloted.

Basically, I have "Action"_"hours" with a possibility of "Action_A_hours, Action B_Hours, Action C_Hours, Action D_Hours" and I want to extract any match of "Action X" and sum all hours that match.

I've been working on this overall for over 20 hours and think I need a change of perspective.


From the attachment:
I want to take the data in the Monday column, and where the string matches in the project overview column "2675_Mechanism Drive_Guard Bottom_Fit" I want to sum all numbers that match from the Monday column. The result i'm looking for is highlighted in yellow.

The difficulty for me right now is that some of the cells in the Monday column can be multi tasked, with the comma delimiter as shown in G3.