Since you are new to this, you shouldn't take offence when I ask if you are inserting the eyepiece into the barlow or just looking directly into the barlow. I will assume though that you are using the barlow, normally, with the eyepiece inserted.
While a barlow will double the magnification, it also halves the field of view, and makes it dimmer. A poor quality barlow (usually they are thrown in with the scope) is next to useless, but even a good one takes a little getting used to.
Of course, having a jiggly mount isn't going to help any and the only solution there is to get a better one.
If you can give us more specs. about your scope, eyepiece(s) and barlow we may be able to give you more advice - although it may add up to "buy a better set-up".
On the other hand, binoculars are a great way to get into astronomy, and you can make a simple T bar mount to help keep it steady.
If I may make one other suggestion: get a (spiral bound) copy of "Nightwatch" by Terence Dickenson before you buy anything else for astronomy.

Keep looking up, and ask when you have questions.

Glenn