Defence builds confidence ...
Great attackers - aggressive fighters - have great defence. In fact, it may even be argued that reason they attack so much is based on them having an excellent defence.
I'll explain why ...
Why is it they people don't attack more often?
For example - why not go for ten armbars a night instead of only five?
The most common reason is that we are afraid of the consequence of a 'failed armbar' - that is, we are worried about losing our good position if it all goes wrong.
Now imagine, that you are the worlds best escape artist from underneath side control - suddenly, you wouldn't worry about blowing your armbar If it doesn't work and your opponent gets on top of you - so what - you will be out of there in a moment anyways - and giving something else a go. So the better your ability to escape - the more likely you are to go for more attacks - because you will not hesitate and start worryig about the downside.
Want to attack more agressively - simple - become better at defence and escapes. You will then be more confident to attack.
On a slighly tangental note - most people feel the pressure when they have everything to lose. Or worse - more to lose than what they actually have.
Case in point:
The great golfer Lee travino - was once asked by a reporter how he coped withthe pressure of a $500,000 putt - he replied that a $500,000 putt was not preesure - real pressure, he explained, was back when he would make a ten dollar bet with his friends, knowing that he only had five dollars in his pocket.
In other words, real pressure is experienced when we put up more than we can afford to lose.
So finally, here's my point: provided that you are confident of escaping side control - then you are not betting more than you can afford to lose and so you will be more relaxed, and more likely, to attack more often.
Being confident in defence is an important part of the elite grapplers mindset - so don't avoid working on escapes and defence. I know it's not sexy - but it will pay great dividends.