While our experiences might be similar to C/7, most of them are false analogies, a classic logical fallacy. Even an arranged marriage brings experience in relationships with the spouse, the spouses family, etc., not to mention years of schooling, family issues, etc. No human reaches a marriageable age without a long, progressive growth process through infancy, childhood, and adolescence. Seven had roughly ten years of non-Borg experience--six of those as a child on the Raven.
Teya, the experience you had with your boyfriend may seem similar to what Seven did, but the analogy doesn't necessarily work. You and your boyfriend were experienced and aware of what the commitment would require of you. As Chakotay wisely tells her, no one can predict the future--something that apparently hadn't occured to Seven. In your case, you knew quite well that you could have predeceased your boyfriend through any number of illnesses and accidents. All anyone can promise someone else is today.
For every analogy that works here, there is another that doesn't. For every person who married the first person they dated, there are others who didn't or who married and then divorced them. For every couple that warned each other about an illness or problem they had before becoming involved, there are some that ended up with a successful relationship and just as many, maybe more, who didn't. In other words, analogy is a weak basis for an argument, because rarely, if ever, are the comparisons valid in every way. Any analogy we use will not include a partner who lived their first six years in space with their parents, finished growing up in a Borg maturation chamber, spent a dozen years as a drone, and then lived four years on a Starfleet vessel interacting with less than 150 other people.
The reality is that Seven's reaction to what the admiral tells her shows her immaturity and reveals that her relationship with Chakotay is not "equal," at all. Her motivation, to keep from hurting Chakotay, might be similar to your boyfriend's motivation, but to say that he was like Seven and you like Chakotay is a false analogy IMHO.
As for Chakotay's weakness, it just seems to me that he picks women who are stronger than he is and who like to call the shots--from Seska, to Kellen, to Kathryn, to Seven.