@Kirsttt91 If these feelings have come on since he started his new job, perhaps you and your husband could first try employing someone a few hours several days per week to help your family?
When you are both properly supported to manage all the family duties -- paid work, children, house etc, you might find that your fuses are not so short and that you aren't so angry with each other.
Employing help would be much less upsetting for the children than trial separation, and cheaper than renting an additional roof. And importantly it might be a happier result for you too.
If he vetoes additional help, then yes trial separation might be sensible if relationship counselling won't suffice. You can't know where the trial will lead - it will depend on lots of factors outside your control - but it sounds like something needs to change.
You might also want to offer to be patient with his new job - after all new employees have to "put in extra" to build the right impression and it is often quite stressful being a new employee - but you might also want to be clear that the current situation can't go on beyond 6-12 months without harming your relationship and family.
One other point - in many countries, trial separation can be difficult to agree - if he refuses you can't force him out of the home unless you have sole legal rights, and if you choose to leave there can be legal complexity taking the children with you because they are his children too, he has parental responsibility (even if he is at work all day) and the status quo is that they live in the family home. On the other hand, given the sort of job he has with long hours, it might not be easy for him to prevent you leaving with the children. For example, unless he thinks of a better or equally appropriate plan to care for the children if you leave (e.g. quitting his job, after school care half the week), or a good reason why it is not in their best interests to go with you (e.g. if you travelled so far that the children had to change schools, or couldn't see him regularly). Some people doggedly refuse trial separation even though that attitude basically seals the fate of the relationship, and leads to a a very unpleasant home environment. In these situations the slow and unpredictable legal system is a pita; also it's emphasis on the status quo. Another reason trial separation can be difficult to agree is because the housing that the 'mover' moves into can affect their legal position in the divorce - for example if it is small and cheap or paid for by a relative, it might be said to be evidence that the individual does not 'need' bigger accommodation (or that they have a source of income from the relative) so they should get a smaller share of the financial split (even though the person who moved only saw it as a temporary hardship (or favour) to try and save their marriage). This argument doesn't necessarily succeed but it means that trial separation is a risk that some people are not prepared to take. If there are friends or family that one of you can stay with, this can make it easier.
I am not trying to dissuade you from the idea of trial separation - just to give you a heads up on what might happen. It's not as easy as the media/tv makes out. But if something has to change, then you have to ride the waves whatever they are. And trial separation may be less choppy and a better outcome than divorce.
Sorry for the long post. Been there done that - so just offering you the benefit of my experience...