Nobody actually knows. We all differ in the experience of side effects. Some meds give us tons that don't give someone else any and others give us few that gives that someone else tons. One way to ease into this is to taper up on the drug, as you're doing, just as when you stop you taper down as slowly as you need to. If you're more comfortable, you can wait a bit before going higher in dosage so you'll be more used to it. A general rule with antidepressants is that they take about 4-6 weeks for most people to notice the positive effects, while side effects start right away. Since you're posting on an anxiety website, know that the usual dosage -- and this is a generalization, as again individuals vary a lot in how well they absorb a particular medication or if they absorb it at all -- is between 10 and 60mg. You can also keep going up in 5mg increments instead of 10 if again you want to slow down the taper up. At some point, though, it might turn out that this isn't going to help you. The fact you've suffered side effects means you are absorbing the drug, but that doesn't mean it's going to work. You might come to realize this isn't your med and have to taper down off of it to be safe and then try something else. All the best.
So, I think Prozac can work very well. And is pretty well tolerated for most. 20 mg is the typical dose for a lot of people. 10 mg is low. I'd go up by 5's and do it slowly if your doctor says to go up. And that slow rise in mg should make the 'getting use to it' easier. Also, it's not a new substance to you like it was when you first started taking it. It's just more. I'd try it. Anxiety is terrible. good luck and let us know how it goes.