If you really want to be happy, value every little moment of life. Spending time with family and friends, singing your favourite song, receiving a surprise, opening a gift, eating your favourite food, laughing from your heart, watching the rain, enjoying the sunshine. Unless we start enjoying what we have we can neither feel successful nor be happy.
Let go of what holds you back in your past. It may seem hard, it may feel like a loss but unless you do, you will never explore new possibilities and have new experiences that could bring a much needed positive change in your life.
Your own life is the biggest inspiration. Learn from your own experiences, follow your dreams and fulfill your purpose. Live it with courage and compassion, you will never lack inspiration.
Learn to accept your situation, learn to accept people and learn to accept yourself. You will find that all this while that overthinking, that arguing and that worrying was nothing but the imaginations of your own mind and if your mind has the power to create it, it has the ability to get over it.