To be honest, many fans on here could have told you about the non-injury related, game attendance logistics. Seats very low behind the sideline are terrible at every football game because you lack depth perception and angles to actually see plays develop. If you have to sit on the sideline, sitting on the Eagles (west) sideline is a little better because you at least are close to the players and see what they are doing on the sideline (and can yell at and mock Howard Eskin too 😁), though on that sideline you also have to worry about the roving TV camera stand set up behind the player benches blocking your view from time to time if you are between the 20 yard lines. I have a friend who is a season ticket holder who I sometimes go with to Eagles games, and his seats are in the 4th row on the Eagles' sideline at about the 30 yard line towards the north/TV left end of the field. I genuinely dislike those seats (and primarily am willing to sit there because my friend gives me a good price and I get to spend some time with him), and much prefer to sit higher in the stadium, at the very least near the back of the lower level. If you don't want to pay extra for club level seats, the first 3-4 rows of the upper deck, which are physically separated from the rest of the seats in the upper deck, are secretly good seats. I'll add that end zone seats, or at least club/upper deck end zone seats, in some ways are better than sideline seats IMO, because you can see plays develop better from behind or in front of the play. (Think about articles you've read that contain embedded videos analyzing plays; they always use an end zone view when examining formations.)
As far as parking, depending on where you are coming from/going to after the game, if you are willing to walk (and I realize you were injured when you attended the 2018 Vikings game, so what I'm about to say wouldn't have applied in that case), parking in the lot over near the NovaCare complex west of Broad Street is a good spot, especially if you are heading south (I-95) or west (I-476/Blue Route via I-95 or I-76/Schuylkill Expressway) or even east (Schuylkill Expressway and Walt Whitman Bridge). You can get in and out of the parking lot easily, and heading west on Pattison allows you easy access to the Platt Bridge (to I-95 South), 20th Street (Schuylkill Expressway eastbound), and 26th Street (Schuylkill Expressway westbound). The general rule of thumb is the closer you park to the stadium, the harder it is to get out of the parking lot after a game. Incidentally, I concur that using transit is a good option; many times when I attend games at stadium complex (Eagles, Phillies, Temple football, 76ers), especially with Eagles games or when I take a day trip to Philadelphia and a game is part of the day trip, I use Amtrak between DC and Philadelphia and SEPTA between 30th Street Station and Broad/Pattison on the Broad Street Line.
P.S.1 If you ever attend non-Eagles day games at the stadium complex (primarily Phillies Sunday games, some 76ers or Flyers Saturday games, or many Temple football games) and are willing to walk, you can almost always park for free during day games at FDR Park, the community park south of Pattison Avenue and west of Broad Street across from the stadium complex. Parking is only charged there when crowds of over 50,000 people are anticipated at the stadium complex, and the gates for the park close at 9 PM (summer) or 6 PM (winter) depending on the month. If you do park over there, just make sure you don't park in the lot for the private golf course that is also located there. (If you enter FDR Park from 20th Street, the golf course lot is on the right, while the FDR Park lots are on the left and straight ahead.) I pretty much always park there for Sunday afternoon Phillies games.
P.S.2 Most NFL teams actually have an on-site pre-game show at the stadium. With the Eagles, it is always on the north side of the stadium outside the Headhouse Plaza. At the Meadowlands, it is on the southeast side of the stadium near where the Meadowlands train lets passengers off. At FedEx Field, it is on the east side of the stadium near one of the access roads from the DC Beltway/I-495. (I don't know where it is in Baltimore or the other couple of NFL stadiums where I've seen Eagles games.)