Track Values in a Cell with a Neighbor Cell Containing Specific Keywords, how?

Hi all, first post here. Not quite sure how to search for this query, everything I searched for online was for SEO type keyword tracking.

I have a budget tracker that spans years. I would like to get a summary of income and expenses at the bottom of each page to feed into a yearly tracker. I want to have a formula that scans a selected area for keywords. When it finds a keywords, it will return the value of the neighboring cell and total it (I just need a total, I don't need to have a list of all instances it finds). Depending on the keyword, income or expense, it will return the value of the cell directly to the left or the right.

So it will scan a range of cells for say GAS, I only filled up twice this month, at $40 the first time and $50 the second time, when it finds gas it will then total up the neighboring cells so the formula at the bottom of the sheet will have $90 GAS.

So the layout looks something like this;