Warning - slightly rambling train of thought follows.
Writing can be really easy sometimes, or really hard. If I've got a specific idea in mind for how a scene goes, then sometimes it just flows out onto the page, and it works great. Other times, it can drip, and no amount of coaxing helps. Maybe I just have to accept that some days will go better than others.
One of the things that can make stuff harder, for me anyway, is characterisation. When I'm writing a scene, I try to be in everyone's head, and have the whole conversation. I tend to get very attached to all the characters, and that usually means that if I'm writing a stressful, depressing, or angry scene, the characters' emotions can get a bit overwhelming at times. More than once, I've had to walk away for a cup of tea to try and calm myself down.
