try natur enemy castbar (NECB). it has bars that will appear when you cast a HoT on something, showing when the HoT will run out, and it updates to account for swiftment too (i.e. if you rejuv and then 8s later swiftmend, it removes the rejuv that you swiftmended from your bar list).
it also factors diminishing returns such as those on roots, bash/pounce or cyclone, for when you need to use those particular skills.