Welcome to full-time freelancing!
It's a constant struggle as you may sometimes be so busy that you have to turn down great invitations to work, and be in the search of good projects the next day.
I wouldn't recommend full-time freelancing without having:
a) money aside for these kind of "difficult times";
b) at least two sources of constant income (like ongoing projects with "offline" clients you trust or hourly projects on Upwork);
c) at least two sources of work or platforms to find clients on (example: if you only go for online freelancing, then you should try to work on at least two platforms, you never know how your account can get suspended on one of them cause of a client or god knows what).
That's one of the biggest downsides of freelancing - the element of surprise when it comes to your finances. Sometimes that's super positive, other times it can be so-so, and... sometimes it's just awful.
I've quit my daily job when I had three stable ongoing projects to work on and a couple of pending proposals. And even so, I still went through 2-3 episodes in these past years when nothing seemed to come together.
I'm in a very fortunate situation at the moment. I have taken twelve months off work to look after my daughter, while my wife went back to work, so we had planned for me not to have any income for twelve months. Anything I earn is a bonus.
I've got about six months left to see if I can build it up enough to continue, and not have to go back to work.
I have found that a subset of my clients seem to receive new funding/assignments at the first of the month every month. I actually schedule work for clients who are more flexible during the 2nd-4th weeks so that I have that first week free for the influx.
Depending on your field, you may see seasonal fluctuations as well.
You're finding out the hard way that you always have to feed the machine with bids.
You're gonna need a savings account too. And yeah, multiple streams of income.
It took me 6-12 months to finally get to the point where I have enough repeat business and enough understanding of how to sell before I got comfortable.
In addition to all the good advice so far, you also have to think of your business plan six months out from now, a year out, etc.
You've got to keep looking for more ways to entice new clients and keep the ones you have now. In general, while working with a client, find out if you can fill another niche for them.
Or while looking at your job feed, look at what is trending as a hot market. Can you broaden your skillset to include it?
Planting little seeds today can reap big dividends later on when you may need it most.
Best of luck to you!