Interesting. If you are eating 5000 cals and nothing is changing, something is wrong. With or without gear, there should be some changes. The first thing I would do is go to your Dr and see what he/she thinks. You may have an issue with digestion or organ funtion that is making it harder to gain. It could only help to find out. If you find out that nothing is wrong, the problem has to be with your diet and training. At your size, you should still be able to make good progress. I'd like to see you figure this out and begin making progress before you start this next cycle. That way, you can make the most out of your time "on" and know how to maintain your new gains when you come back off. 

Not knowing all the details of your life, I can only guess what you need to do and what is off, but remember, just because something was working before doesn't mean it will keep working. So look at training. Then look at carb timing. Possibly look at fats. Maybe you still need more calories or change the foods you're using? 5000 sounds like a lot but I have seen guys that need to eat this much, often ectos and often guys that have a very active physical job. 

If you're interested in working with me directly on this, hit me up, here at Naps, Next Level Nutrition .