I had this opening played against me. I played black.
en.lichess.org/i8PYe0tD#9Is there anything black can realistically do against this opening without losing position?
2 e3 is passive. You can play many good moves then e.g. 2...Nf6, 2...e6, 2...c5, 2...g6. Your 2...Bf5 is not bad.
Instead of 3...dxc4 it seems more logical to defend your central pawn with 3...c6 or 3...e6 or even 3...Nf6.
Instead of 4...Nc6 you could play 4...e6.
Instead of 5...Na5 you could still defend with 5...Nh6 6 Qxb7 Bd7. You are then down a pawn, but you gain some time attacking the queen and the bishop.
Stockfish gives 5...e6 6 Qxb7 Nb4 as defence.