You have a situation that calls for two antennas. I would prefer outside mounting for both antennas. However, you have the signal strength to attempt attic mounting if the attic and roof construction is not metallic
An RCA ANT-751 aimed at 105° compass should offer good coverage of the stations to the ESE. Though in the attic, a Winegard HD7694P would not be overkill.
A two or four bay panel antenna (DB-2 or DB-4 for example) aimed at 20° would cover the NE group of stations. Go larger if mounting in the attic.
There simply are no practical consumer grade products that would reliably combine all these signals from those two sources. (It's done with tens of thousands of dollars worth of equipment in a CATV head-end.)
I think the most practical method for users of conventional TV sets is to wire each antenna separately to each TV. Then select the desired antenna with an A/B switch at each TV.
There are
computer and network attached tuners... You may or may not want to go down that road given your existing investment in TV sets.