Sounds like you coped fairly well in a difficult situation. Calling for help is an option you should always have up your sleeve
When things go wrong navigationally, above all else, get yourself somewhere known. A town, a known waypoint, anything that is KNOWN.
On the way there, plan a route to where you want to be from that known position. If you're there already, just orbit it in good wide orbits that give you plenty of thinking time.
Then resume your ded-reckoning from there.
In general also use useable landmarks. Let's say you're flying 200 miles from obscure airfield to obscure airfield - the best bet is to fly 5 miles from obscure airfield A to the nearest town/river junction / funny-shaped-hill: something you can't mistake. From there, fly your route to an equivalent that is close to airfield B, so with any luck you're then within a few miles of your eventual destination, and can't miss it.
The odd distinct landmark en-route is great as well, even if that means a small dog-leg, as it allows you to reset your navigation from time to time.
And if you work out the difference in time between the difficult to fly direct route, and the easier to fly dog-legged route with start and end route points, invariably the loss is only a few minutes, so don't worry about it.
Regarding controlled airspace. When I did my commercial training and test I used to plough straight through it, with appropriate clearances and radio calls along the way - because that was what was expected of me. In the real world when I'm using an aeroplane to get from A to B, I've learned over the years that crossing clearance are not always the easiest or most efficient way through. A required dog-leg, or couple of minutes trying to get that crossing clearance can lose all the time the crossing should have gained you, whilst a planned route around / over / under can often be faster in the real world. So, If weather or terrain make over/under unlikely, what I'll probably do is plan "around", but make an option to ask for a crossing clearance and cut the corner of my own route, resuming it at a known waypoint.