as others have said … leave … cut your losses. if you want to fix it, you should have been engaged in that process much earlier. No MVP yet, what happens when someone is ready to invest? you all scramble and make something which does not sell/work? Plus, when will you start generating the user base ??
You need to take a break and realistically reassess your situation. What is your personal return on the 5 years invested AND your projected ROI? Your job is to take care of yourself first, your family and children AND THEN other entities. When the “startup” company goes under and releases you, most probably without any safety net, you will be in for a rude awakening :-(