My timeline turned into your timeline after the actions that were taken. There were two problems, the first was a global war, the second was a computer failure due to the first problem.
We managed to buy time and delay the start of the war and create the right conditions to convert all computer systems to 64 bits, this led to the existence of yours (i.e. our worldline).
In the future my worldline managed to fix a massive computer glitch after 2038, but this has led to the fact that there are now two versions of worldlines.
The first version of the worldline is where there was a war in 2015 and in 2038 there was a collapse of all computer systems that was fixed due to actions taken in the past (1975 and 2000).
The second version of the world line came about because of the actions taken in 1975 and 2000, which led to the war happening in 2015, the computers had time to convert to 64 bits, but in this version there is still a war in the next 12 years.
In other words, trying to fix the main worldline resulted in your worldline, because the computer had to be taken in 1975 from someone else's worldline so as not to change the timeline of events of the mainline, but this resulted in your worldline existing and it now overlaps with the mainline.