Full body 3x a week can definitely work, but it heavily depends on your individual recovery ability and overall program design. Since you've been lifting for 6 years, you probably have a solid foundation, but if you're feeling like a soggy slice of pizza lately, it might be a sign to reevaluate your approach. Make sure your nutrition and sleep are on point because if you're not fueling properly or getting enough rest, even the best program won't help you recover.
Consider starting with a lower volume or frequency, maybe 2x a week, and see how your body responds. You could gradually increase the intensity and volume if your recovery improves. Also, implementing deload weeks or lighter sessions can help manage fatigue. Listen to your body; it will tell you what it needs. Don't hesitate to modify your workouts as you go along, and remember that training is a marathon, not a sprint.