Travel phobia & last minute change of plan

Hi, please support me if you can with this. I have had a travel phobia for the last 20 years, mainly around feeling trapped in vehicles and not being able to get out of I want to. I was planning on driving 3.5 hours to see my family tomorrow despite the no doubt heavy holiday traffic and fear of breaking down or crashing that I always have. This morning on my way to get petrol ahead of my trip I got a flat tyre and had to call the breakdown service and then take the car to a garage. I was shaking so hard and crying the whole time even though it was just a puncture. The car won't be fixdd until Fri and my mum wants me to get the train instead tomorrow. I am filled with dread and anxiety as I was already nervous about travelling let alone on public transport where I am not in control. I am sad to think of missing out on seeing my family after 2 years of being apart but terrified of travelling. I just want to retreat from everyone and everything. I can't stop crying. What shall I do?