C DLL injector doesn't work twice [C++]

Code

#include <iostream>

#include <Windows.h>

#include <string>

#include <fstream>

#include <TlHelp32.h>



using namespace std;



void error(const char* title, const char* msg) {

    MessageBox(0, (LPCSTR)msg, (LPCSTR)title, 0);

    exit(-1);

}





BOOL __stdcall GetProcessID(const char* window_title, DWORD &proc_id)

{

    HWND hwnd = FindWindow(NULL, (LPCSTR)window_title);

    if (hwnd == NULL)

        error("Finding window", "Couldn't find window");



    if (!GetWindowThreadProcessId(hwnd, &proc_id))

        error("Process ID", "Couldn't find process ID");



    cout << "PROCESS ID: " << proc_id << endl;

    return TRUE;

}



int main()

{



    DWORD proc_id = NULL;

    const char* window_title = "Spotify Free";

    const char* dllName = "Test.dll";

    char dllPath[MAX_PATH];



    if (!GetFullPathName(dllName, MAX_PATH, dllPath, nullptr))

        error("DLL search", "Couldn't find DLL");



    GetProcessID(window_title, proc_id);

    if (proc_id == NULL)

        error("Process ID", "Couldn't find process ID **ERROR**");



    HANDLE h_process = OpenProcess(PROCESS_ALL_ACCESS, NULL, proc_id);

    if (h_process == NULL)

        error("Process Handle", "Couldn't find process HANDLE");



    void* allocated_memory = VirtualAllocEx(h_process, nullptr, sizeof(dllPath), MEM_RESERVE | MEM_COMMIT, PAGE_READWRITE);

    if (!allocated_memory)

        error("Allocated memory", "Bad allocated memory");



    cout << "ALLOCATED MEMORY addr: " << allocated_memory << endl;



    if (!WriteProcessMemory(h_process, allocated_memory, dllPath, MAX_PATH, NULL))

        error("Writing process memory", "Error writing process memory");



    HANDLE h_thread = CreateRemoteThread(h_process, nullptr, NULL, LPTHREAD_START_ROUTINE(LoadLibraryA), allocated_memory, NULL, nullptr);

    if (h_thread == NULL)

    {

        cout << GetLastError() << endl;

        error("Creating remote thread", "Error creating remote thread");

    }

    CloseHandle(h_process);

    VirtualFreeEx(h_process, allocated_memory, NULL, MEM_RELEASE);

    MessageBox(0, "Successfully injected!", "Success!", 0);

}

Code

// dllmain.cpp : Defines the entry point for the DLL application.

#include "pch.h"





BOOL APIENTRY DllMain( HMODULE hModule,

                       DWORD  ul_reason_for_call,

                       LPVOID lpReserved

                     )

{

    switch (ul_reason_for_call)

    {

    case DLL_PROCESS_ATTACH:

        MessageBox(0, "Hello from inside CSGO!", "MaMan!", 0);

    case DLL_THREAD_ATTACH:

        MessageBox(0, "Hello from inside CSGO! - THREAD", "MaMan!", 0);

    case DLL_THREAD_DETACH:

    case DLL_PROCESS_DETACH:

        break;

    }

    return TRUE;

}