From my experience the will to change is only one factor - an important indeed - but far not the only one being sufficient to trigger and implement change. Here is a list of the most relevant factors from my point of view in the order of relevance during a change phase:
Yes, it is important that you feel suffering - because otherwise the psychological strain is missing that make you act.
You need to understand that you are a - the - major contributor to your suffering and to bad situations. You need to accept that you can at best change yourself and there is only a very slim chance to change others.
- Will to change
The will to improve yourself and the believe that you are able to change yourself. It is the point where you say to yourself: "Things can't continue that way.", "I have to change.", "This road has a dead end." and so on.
You need to analyze the problem, to identify the same problem in different situations (often in several different situations the reason for getting into trouble is often the same). And you need the ability to find the reasons for symptoms and digging for the real sources.
When you found reasons you need to understand where the mistake or error initially occurs and that your decisions or automatic responses in those relevant situations are unhealthy. It is the moment when you see alternatives that are more healthy. It is the point where you change your general philosophy in the affected area of your life. This is one of the most important factors: Every change that you are implementing without the appropriate insight then it is forced change that consumes much energy and often cannot be implemented for a longer time and you will suffer relapses more often.
- Energy and drive
You need the appropriate energy (enough rest, food, friends and all other kind of support) and drive (mental power, self-confidence and courage) to implement the change. The will to change can be the energy drink for the "power hour" you also must be in general physically and psychologically healthy enough.
- Persistence and practice
Never give up and practice your implementation whenever adequate and appropriate. When you fail you have to try again or review your insight and maybe continue with point 2 or 4.