This game was decided on move five, and the four moves after it were all about the same knight.
Nine moves is not much to work with, so this is less a review than a diagnosis. The good news is that it is a single, very fixable decision repeated four times.
5...Na5 — the capture came first
Forty-one seconds, and -0.2 became +1.5. 5.d5 attacked your knight — but James's knight on f3 was already attacked by your e4 pawn, and had been since move four. That was the move: exf3, and the position stays about level at -0.1.
When both sides have a piece hanging, the one who captures first wins the argument. Na5 answered an attack by moving, which handed James a reply that saved his knight and gained: 6.Nd4.
6...g6 — the way home, and it closed
Fifty-four seconds, +1.5 to +2.3. After 6.Nd4 the knight on a5 had one useful move left in it, and that was Nxc4 — taking the pawn it went to the rim for in the first place: Nxc4 Nxf5 Qf6 g4 Bb4 Qc2. You are still much worse there, at +1.5, but the piece is back in the game and you have a pawn for the trouble.
g6 defended f5 and left the knight where it was. Then 7.Qa4 attacked it again and 7...b6 spent another move holding it. Three moves given to a piece that never played.
A piece on the rim has a route home and the route closes. Take it while it's open, even when it looks like it costs something — being a pawn down with all your pieces beats being level with one of them not participating.
8...Bg7 — a second piece onto the fork square
Twenty-five seconds, +1.8 to +3.0. James's 8.e3 had just given you a moment, and the engine's move was Nb7 — the knight, again, coming home: Nb7 b4 Bg7 Bb2 Bxd4 exd4, still +1.8 and still a game.
Bg7 instead put the bishop on the long diagonal, where the d4 knight's jump to e6 hits it at the same time as the queen. 9.Ne6 is defended by the d5 pawn, and dxe6 doesn't rescue it because that opens the a4–e8 diagonal onto your king, which is what 7.Qa4 had been doing since move seven. The engine's line was Bxc3+ bxc3 b5 cxb5 dxe6.
The knight jump to e6 had been available for two moves before it landed.
Phase notes
There is only an opening to talk about. 2...f5 is not what lost this — going from +0.1 to +0.5 is a normal price for an ambitious second move, and it is a perfectly reasonable way to play the King's English. The damage was all between moves five and eight, and it came out of about two and a half minutes of thinking: forty-one seconds on 5...Na5 and fifty-four on 6...g6, the two moves that did it.
Profile check
This is the item that has to change. Your file has said for a month that you don't lose games in the opening — that the opening is the reliable part. This game was nine moves long and the evaluation was +1.5 after your fifth move. Put it next to the Caro-Kann earlier today, where you came out of a quiet Exchange at about -0.9 with nothing flagged at all, and the opening is no longer the safe part of your game; it is where both of today's losses were decided. The reply-check habit is confirmed again on top of that — 8...Bg7 stepped onto a square a knight jump was already covering.
What to drill next
- The position before 5...Na5 — Black to move, both knights hanging. Find exf3 and beat the engine from here three times running.
- Zwischenzug puzzles — exactly this shape: something of yours is attacked, and the answer is a capture somewhere else.
- King's English, Reversed Sicilian theory and explorer — you have faced this from James three times in five days and it is worth knowing what Black is supposed to do after 4.d4.
When a piece of yours is attacked, find your own capture before you find it a square.