The most common way to resolve any suspension is downward by step. Moving upwards is done, but suspensions are generally a tension-release technique, so in this case the standard resolution would be down to a D#.
But there’s a bit more to it here. This isn’t really a true suspension, since the E isn’t actually held over in the voicing you have here. As luser droog says, you can move the harmony beneath the tone. This is also pretty common when delaying the resolution (i.e. keeping the suspended tone for more than one harmony change and delaying it’s resolution further), but if you don’t move the tone at all, then it pretty much loses its character as a suspension since there’s not really a resolution.
The big question here is, what do you want the function of this last measure to be? You have some kind of B chord which you said is going back to e min, so we strongly expect it to be tonicizing. The chord options depend on the choice of harmonic rhythm. Changing it up in the last bar of a phrase is very common, so here you could do something like; Vsus4 — ii5/6 — V , so two quarter note and one half note, or a little more involved; Vsus4 — ii5/6 — V3/4 of V — V , both of these resolving the suspension in the least harmony. These are just a few possibilities, you could also introduce the suspending note in that last measure and then resolve it in a later harmony within the same measure., and you even forget it as a suspensions and make it a pedal through the whole refrain.
You mentioned the unresolved quality is grating, which it should be. The purpose of these suspensions (and related techniques) is to cause tension that makes the subsequent relaxation more satisfying/powerful. This particular suspension very, very strongly wants to resolve to the leading tone, D#, which will emphasize the 7 – 1. The scenario you’ve set up here is an authentic cadence, so if you don’t resolve that E to the D#, than it will sound grating or unsatisfying (though this doesn’t at all mean you can’t leave things unresolved, grating is mild compared to some musicians’ works).
I would encourage you to think of it in terms of where this measure is leading, and that will decide your set of options. If you want it to move back to the e min and consider this tonic, than the options I wrote above should give you some ideas. But if this isn’t the case, there are a huge array of things you could do, it just depends on where you want it do go.
And a few last personal observations (to take with a grain of salt, since I've seen only a tiny amount of what you’re working on and composition is very subjective):
You mentioned that the song is in e min, but we have a refrain in e min. Refrains generally have something that significantly distinguishes them from the rest of the piece, and modulating is a very effective way. I’d consider putting the refrain in a different key, OR setting up something where the e min is destabilized as the tonic, something like thinking more in the key of the relative major, G, is very common. Similarly, you said you were trying to keep the tension. A B going to e at the repeat of a phrase is very stable, even with fairly colorful chords, this root movement is very tonicizing and will feel very firm. If you want tension, try dominants that are less standard as well as movement to something other than tonic. And on the note of root movement, it may be very beneficial to play around with the bass line here. Right now it’s only E-B, so again, very stable. Just inverting chords can have a big effect on the strength. Hopefully some of this is helpful!