Definitely. If you're eating a normal amount of calories and then adding 500-600 calories of heavy cream? Absolutely. Just because there is no reason to fear the fat, and just because it provides health benefits, doesn't mean you can't overdo it. Obviously though, if you're accounting for the cream and coming in within reasonable calorie limits, it's something else. Whether that's stress or some other factor is something you'll probably need to experiment with. This stuff takes time, and unfortunately no one here is going to be able to tell you with any accuracy what's wrong. The best we can do is offer suggestions, but only if you provide a bit more detail about what you've been eating, your activities, supplements/medications, etc..

So the best I can do from your post is:

"Could this be make me gain weight? Will the cream make me gain?"

Could be... Possibly...

"I also have been under a lot of pressure and have a lot of stress as well, could this be the problem?"

... Could be :P

Lack of sleep and stress could easily do it. You could eliminate the cream and see what happens.

I find that dairy really helps me gain weight, I am not sure why. Since I don't need that weight I try to avoid it when I would rather lose some.

I second the idea of switching to coconut milk for a week as a trial. It is really yummy in coffee.

I'm a nurse in long term care, the main breadwinner of my family...two big sources of stress in my life. I can tell you that lack of sleep and stress will hamper weight loss, physically and emotionally. Lack of sleep and stress can lower your judgment and make you more prone to poor food choices. I eat chocolate but when I'm under stress, I want the shitty chocolate with sugar in it. Not as much though. I've been adhering to a low carb/paleo approach for about a month and my sugar cravings have decreased significantly.

Number one thing you can do is to change your environment. Don't have the trigger foods in your house. For me, it's workplace avoidance and substitutes. I can't stomach green tea by itself in the morning. Black coffee is what I can handle on its own. Coffee by itself won't make you gain but if you add cream and sugar in excess it might. I'm addicted to heavy cream now too. I'll be keeping an eye on my weight with the heavy cream myself.

Fasting for spiritual reasons is fine as long as you realise that spiritual fasts usually overturn something serious mental baggage. I do a spiritual fast every year for Lent. They're tough because it clues me in to how addicted I am to food (sugar) to satiate my emotions.