I think you received lots of low quality backlinks from untrusted sources.
TF is calculated based on trustworthy sites linking back to your site. If you have hundreds of backlinks from low quality sites or sites not trusted by majestic, your TF will drop.
Low TF and high CF is usually an indicator of a spammed site with low quality backlinks.
Nobody can actually tell you if you will rank higher or lower in SERPS. Google do not use Majestic Metrics to determine your position in SERPS. So... you may or may not see improvements on google rankings.
If you were thinking to sell this domain, this has definitely hurt it. People usually check these metrics before buying.