Weight Watchers offers that group support. Forums and message boards offer the same thing. WW only tells you that you must eat less (fewer calories) and move more - and you already know that.
You don't HAVE to go to WW because you already know what WW shows you will work: a caloric deficit substantial enough to show you some results fairly consistently. The points system (and now, the more up-to-date points plus system) just gives you a budget of points (calories) and you decide how to spend them. Any old - even any really, really old - WW cookbook will help you see the differences among foods. At a used book sale (at your local library, for example), you will even find books that still have that little WW slide-rule-thingy included. It had fiber, calories and fat to figure the points. Today, the points system uses protein, carbs, fat and fiber.
People lost weight very well with the old slide rule and the old points and observing their points (caloric) budget. The benefits of using the new points plus system are great - zero points for fruits and almost all vegetables, for example. But you know the basic idea is exactly the same. Watch what you eat! Be very specific about what you ate and what was in it and HOW MUCH you ate of it. Tracking food is an exercise that many experienced WWs don't need after years of eyeballing portions and taking note of the fat content of foods. Some WWs track food intermittently - when they start to slide or plateau - or just do it out of habit. This is all that WW is about: staying on plan to ride out the slow periods and then see even more weight loss.
(As you lose weight, WW gives you fewer points!)
You don't need to go to WW. But some sort of accountability (weighing in weekly and having weight go to the computer record at WW and into your booklet) and some sort of feedback (meetings) make it all a conscious effort with consequences. There are other ways to do those things without WW. Any diet, if you stick to it diligently, and it ensures you take in fewer calories than you expend, will work!