you are horrendously underleveled and underequipped (for comparison this is my save just before venture in the optional dungeon). going forward will be only harder and harder because you need to skip more and more fight because you cannot overcome them, thus reducing your xp and money, resulting in a weaker party. most of your party have some equipment slots empty and you miss some status immunity pin (a pillar of TLS combat strategy is equip everyone with it, starting with the mage/slave one)
my advice is restart the game from the beginning and be thoroughly in monster elimination and equip searching [and remove all the equipment kai and altia have for example]. don't be shy and use your money for acquiring a few of fundamental pieces of gear (starting with butplugs for succubi, steel armor, helm and weapons for fighters). bring alwasy an helaer (at least for the first two chapter, so for you is qum) and don't leave anyone death after a fight and use buffing stats skill everytime you don't need healing. robin and aka are your heavy hitter, pamper them with the best gear you can afford is a good thing, refeer to this page for good and easy to miss iterms.