There are some medical strains that are purposefully bred to have the least amount of 'high'. And also sounds like a problem of overdosing, if you have trouble

There are some medical strains that are purposefully bred to have the least amount of 'high'. And also sounds like a problem of overdosing, if you have trouble concentrating or thinking you likely took in more than a few times more than you actually needed which is very easy to do without tolerance combined with modern weed. One hit of high-quality shit these days will put entire joints from the past to shame. Also there are more than a few people who have a hyper-sensitivity to weed which can make it worse.