When we make any change in life, when any door closes, we don't always know which new doors will open. We will never know how each action is going to change things, but as long as we stay alert to the possibilities, we can keep moving forward. Closing a door is hard. Making the decision to move on is hard. Stepping out from the ledge and falling in to the abyss of possibility is hard (and can be quite scary).
Just keep pushing forward. With defined goals, we know what we are chasing even if we don't know how to get there. Every day, things will change and we have to remain open to the possibilities. The key is to make sure you are chasing and not running away. When we run away, we are trying to move forward without keeping our head up and our eyes fixed on the possibilities. It's impossible to really move forward when you are running away and our problems always seem to catch up.
Before making a change, make damn sure you aren't just running from your problems. Know what you want and chase it.