You’ll be happy to discover that one of the most important Christian mystics in history, Emanuel Swedenborg, wrote an entire book on love in Heaven. You can download a free ebook here: Conjugial Love: Redesigned Standard Edition
Heaven, far from being a loveless place, or worse, dictated by what people do here, is a constantly changing place and is not at all bound by material existence. Anybody can have any kind of experience they want there. If you wish to have love, then certainly you can have love and marriage, and of course sex.
Of course, in order to find love in Heaven, you must actually go to Heaven after you die. The most consistent way to do that is to make the decision and commitment to pursue serving others over self. If you’ve found yourself in constant fantasies of self-gratification, then when you die, you’ll slowly find your authentic self, and then a group of people that share that.
If that authentic self is incompatible with true love, then you won’t be able to attract a mate. Instead you’ll have random encounters with random people governed by gratifying selfish desires.