Probably the first step is also taking stock of the entire situation and letting go of what needs to be put down. It's really much easier said than done when there is inevitable attachment to the matter, especially when so much hard work and effort has been put in. Or perhaps the matter was ended abruptly with less than just methods. But if you believe everything happens for a reason, then this statement itself explains everything elegantly and simply. It is what it is, things happened the way it happened.
To neither be affected, nor try to empathise about the people and circumstance, might be the best way to absolve yourself of the situation and help yourself put down what needs to be let go of. Detachment from the persons and situations will probably give the mind space to grasp the bigger picture.
And just know that the universe always has your back. What you seek, you will always get.