The phrase "actually not enough" is correct and usable in written English.
It can be used to express that something is insufficient or inadequate, often in a context where a contrast or clarification is being made.
Example: "While the budget seemed generous at first, it is actually not enough to cover all the expenses for the project."
Alternatives: "truly insufficient" or "genuinely inadequate".
In the years since the economic crisis hit, it's become quite apparent that there are actually not enough lawyers out there — at least, in the right places.
It's actually not enough in modern business; you have to be hugely, insanely profitable to build a lasting business in the modern economy.
However, building a good model is actually not enough: the performance must also be proven.
Actually, not enough young people study chemistry today, so employers have a hard time finding qualified employees.
Although raceway pond has a low estimated energy cost of 3.7 w/m3 (Jorquera et al. 2010), this is actually not enough to provide sufficient mixing, which results in poor mass transfer, as well as limited cell movement in vertical direction (Mendoza et al. 2013a, b; de Godos et al. 2014).
Others say that, actually, not enough is being done to explain to students that they won't need to pay upfront for university.
Some could argue it's a ruse – but it's actually not bad enough to be fake.
Very often, the audience hears us asking stupid questions because, in the moment, we were actually not smart enough to get to the good question".
The left argues that they're actually not ambitious enough; the Center for American Progress, for example, hits Mr Romney for scoffing at the idea of "green jobs": 2.7m of them are "right in front of ya, Mitt".
But, what I find admirable and even more fascinating about Lupita Nyong'o, besides her stunning good looks and her amazing fashion sense, is her own work to highlight another group of people who have been historically ill-treated for actually not having enough color at all.
Anna Gunn's character on 'Breaking Bad' is actually not strong enough.
