You don't want to force your writing so don't make yourself do it but if you have a deadline just be aware of it. If you want to get something done set a deadline and if nothing is coming to mind then do some research that may help you think about it.
When I know I need to get some parts finished I sit at my laptop and have the novel open, and I sit there sometimes for quite a while before writing. Ill watch something or throw a ball around before I get myself back on track, if you have a phone download "evernote" when you get an idea bash it on there and when you get a chance get it down when you get back to your writing.
What is important is writing to the best of one's ability, always trying to improve but - most of all - keeping it enjoyable. :-)
When I was writing my manuscript I set myself a minimum target of 500 words a day.
Graham Greene said he writes 300 words a day. That's 2100 words a week, and 109,200 words in a year. More than enough words for a novel.
I would be surprised if an agent would be interested in an author who seldom writes. They are more likely to be interested in completed manuscripts.
You don't want to force your writing so don't make yourself do it but if you have a deadline just be aware of it. If you want to get something done set a deadline and if nothing is coming to mind then do some research that may help you think about it.
When I know I need to get some parts finished I sit at my laptop and have the novel open, and I sit there sometimes for quite a while before writing. Ill watch something or throw a ball around before I get myself back on track, if you have a phone download "evernote" when you get an idea bash it on there and when you get a chance get it down when you get back to your writing.