Considering a great dane & need insight!!

Hi! Me & my boyfriend are wanting to get a dog together as we both grew up with dogs but still havent gotten one since we’ve moved out! We both love big dogs but since he has a longer work schedule & i work from home we both agreed that we want to make sure we (and most importantly I) can truly take care of whatever breed we get. He just really thinks we should get a bigger dog that can be trained for protection since im alone throughout the day and it would make him feel better, but because of my own mental and physical struggles i get overwhelmed with repetitive movements easily (i.e. my family has an improperly trained malinois who barks, jumps and mouth leads like crazy and i know its not his fault but i cant be around him for long periods due to this) and cant do unlimited energy bursts like you would need for a typically working dog (aside from the normal to be expected puppy stages)but from the research i have done on great danes so far i think theyre a better match. I can handle high maintenance as long as its not also unbounded high energy:) i know theyre super expensive to properly care for and thats not much of a problem for us but id love some experienced great dane owners insight! I take my animals incredibly seriously and i dont want to somehow misread a breed and take improper care of it! I love all animals & dogs but i know some are better matches for other owners for their own well being:) any insight would be greatly appreciated! or any breed recommendations you think you be a better fit:)