Good post. Guys--- the OP is 5'6". He's SHORT! 145 looks a helluva lot different on him than on what you are imagining.
I still think he needs to gain significant weight, but he is not looking like "the machinist" here. Some guys that height look pretty decent at 150-160.
OP-- to answer your question, eating is a very individual thing. but....6 days xardio + lifting ia almost surely going to require more than 2000 calories! Also you can get stronger through CNS adaptations, which are less metabolically "needy" than muscle gains. But I would suggest increasing calories.