Trouble
Unfortunately, a problem has occurred in with our division's project, so I have to support it? Do you mean, you are "reluctant to support it"?.
I'm going to go the office tomorrow because the deadline is next Monday.
There are lots several of elements we that make OR have made the project problematic, but I think OR it appears the causes of trouble difficulty are derived from wrongful OR incorrect estimation and expansion of overreaching scope.
It is difficult for us to predict what the problem has occurred  the consequences will be, so we should anticipate these by increasing the  prepare extra budget.
In addition, controlling scope is also significant important for the project in order to avoid trouble  difficulty.
Our clients' demand is are gradually increasing getting wide do you mean our client base is getting bigger? ; therefore we have to handle what they want to do should aim to implement their demands within the budget OR adjust the budget to reflect this increase in demand. 

Trouble

Unfortunately, problem has occurred in our division's project, so I have to support it.
I'm going to go office tomorrow because deadline is next Monday.
There are lots of element we make the project problem, but I think the causes of trouble are derived from wrong estimation and expansion of scope.
It is difficult for us to predict what the problem has occurred, so we should prepare extra budget.
In addition, controlling scope is also significant for project in order to avoid trouble.
Clients demand is gradually getting wide, therefore we have to handle what they want to do within budget.