I thank GOD that this works kind of

main.go

@@ -60,10 +60,28 @@ func createSession(session Session) error {
 	// Get a handle to the sessions collection
 	sessionsCollection := client.Database("authentication").Collection("sessions")
 
+	// delete all sessions for the user from the sessions collection
+	_, err = sessionsCollection.DeleteMany(context.Background(), bson.M{"username": session.Username})
+
 	// Insert the session into the sessions collection
 	_, err = sessionsCollection.InsertOne(context.Background(), session)
 	return err
 }
+
+func deleteUserSessions(username string) error {
+	// Connect to the MongoDB database
+	clientOptions := options.Client().ApplyURI(URI)
+	client, err := mongo.Connect(context.Background(), clientOptions)
+	if err != nil {
+		return err
+	}
+	defer client.Disconnect(context.Background())
+
+	// Delete all sessions for the user from the sessions collection
+	_, err = sessionsCollection.DeleteMany(context.Background(), bson.M{"username": username})
+	return err
+}
+
 func getSession(sessionID string) (Session, error) {
 	// Connect to the MongoDB database
 	clientOptions := options.Client().ApplyURI(URI)
@@ -1116,43 +1134,6 @@ func successSignin(w http.ResponseWriter, r *http.Request) {
 		return
 	}
 
-	id := uuid.NewV4()
-
-	// Create a new session object
-	session := Session{
-		ID:           id.String(),
-		Username:     r.FormValue("username"),
-		CreationTime: time.Now(),
-	}
-
-	// Connect to the MongoDB database
-	clientOptions := options.Client().ApplyURI(URI)
-	client, err := mongo.Connect(context.Background(), clientOptions)
-	if err != nil {
-		http.Error(w, err.Error(), http.StatusInternalServerError)
-		return
-	}
-	defer client.Disconnect(context.Background())
-
-	// Store the session in the database
-	err = createSession(session)
-	if err != nil {
-		http.Error(w, err.Error(), http.StatusInternalServerError)
-		return
-	}
-
-	cookie := &http.Cookie{
-		Name:     "session_id",
-		Value:    session.ID,
-		Expires:  time.Now().Add(24 * time.Hour),
-		HttpOnly: true,
-	}
-	http.SetCookie(w, cookie)
-
-	username := cookie.Value
-	fmt.Println("printing username from cookie value")
-	fmt.Println(username)
-
 	err = tmpl.Execute(w, data)
 	if err != nil {
 		http.Error(w, err.Error(), http.StatusInternalServerError)
@@ -1520,5 +1501,16 @@ func signInHandler(w http.ResponseWriter, r *http.Request) {
 		http.Error(w, err.Error(), http.StatusInternalServerError)
 		return
 	}
+
+	cookie := &http.Cookie{
+		Name:     "session_id",
+		Value:    session.ID,
+		Expires:  time.Now().Add(24 * time.Hour),
+		HttpOnly: true,
+	}
+	http.SetCookie(w, cookie)
+	fmt.Println("printing username from cookie value")
+	fmt.Println(username)
+
 	http.Redirect(w, r, "/profile", http.StatusTemporaryRedirect)
 }