The wall under the 1st floor (front garden facing) large window
has two vertical cracks running down. You can fee the air coming through these cracks. I think th wall between these cracks is bulgingalso. Can anyone help with how to repair this or whow I should be calling?
This sounds to me like you have structural problems and it is more that a quick DIY fix. I think you should look for a reputable local builder a member of National Federation of Builders or the Federation of Master Builders for example.
howtomendit.com for free repair help, information and advice.
Try fixfault.com to fix windows and doors.