I used to have a career in executive search ("headhunting"), and I was often asked for interview tips by candidates and friends: "what do I need to say or do to make sure I land the job?".
My answer usually surprised them: don't try and fit the job by pretending to be someone you're not, because if you do land the job, it will be bloody hard work to not just do the job but also keep up the illusion...
Yes, we all need a job, more or less desperately, but for most of us, what we really want is work which suits our abilities and personality. So why pretend to be someone we're not?
In an ideal world, you show off your differences, and you are liked for them and get the job. Or if they don't like your differences you don't get the job and are better off for it.
The same goes for couples: if you pretend you love football, when really you couldn't care less, you either disappoint your partner when you reveal the truth, or you'll spend many boring hours watching football games...
If you only show your meek and mild side in order to seduce your partner, what will happen when you show the tiger in you?
If you need to pretend to be someone you are not in order to please your partner, ask yourself: are you really the right person for them? Are they the right person for you?
Be yourself, you're good at it!
And if being yourself doesn't get you what you want or what you need, therapy could help you find ways to change into a better - not different! - version of yourself... or just to learn how not to give a f*ck!