I've been with my partner for over 7 years, and am having similar issues. I didn't come out to him when we met because I was in denial/hoping he would fix me. I'm in a place where I'm about to end the relationship with him, even though we have pretty much had a good relationship, because of my own need for space and a combination of all of our mental issues... so I very much feel for you, even if our situations are slightly different.
Honestly, it seems like you might need to get out of this relationship. You say it hasn't been a super great relationship lately, hasn't been romantic for a while, etc. Those are signs that you could be in a better relationship with yourself, someone else, nature, god, or just-not-this-boyfriend.
You could definitely break up for other reasons, and don't even have to mention the gender stuff. You could theoretically still work together in business, even if you are no longer able to be romantically involved, or even live in the same space. Financially, you could maybe make this work if you saved up for some period of time, right? Like, get enough savings for a few months rent on another place, and while you save money by not going out, spend the time you would have spent going out looking for work somewhere else?
Also remember that you can't cause him to have a relapse or "drive him to drink" -- those things happen because of his emotions, reactions, responses, and in some cases because of his choices. If you need something for your sanity, you can't put his sanity or sobriety before your own. That is his responsibility.
I don't see anything wrong with exploring your identity online. Many folks here would say that your friend
does know the real you, and the non-real you is the one living daily (offline) life. Sending fake pictures or telling lies can be an ethical issue, but if you want to be close with someone, eventually taking that risk and coming out to them becomes something you have to decide. I lied about my age to join an 18+ forum when I was 14; I'm still friends with a lot of the people there even though they eventually found out about that.
I don't know if you have romantic feelings for this person, but you could always tell your boyfriend you've met someone else, if you needed an easy out from the relationship. I know that sucks and probably will screw up your working relationship and living situation... but if you need to get out and have space to become your true self, it might be worth it.
Being in a monogamous relationship with an alcoholic or addict, or any person with severe mental health issues, is extremely difficult and not necessarily noble. The relationship can lose a lot of reciprocity so that you are constantly caring for this other person and neglecting yourself -- and they're not caring for you either (in any material way). So what happens to you? Plus, you being there as a caretaker sometimes makes it so that they don't have to take care of themselves or love themselves or work to make their own lives better.
I understand if you want to stay with him, for whatever millions of reasons you might have that you didn't mention here. Or even if it's for the basic financial reasons that you mentioned, about owning a business together and having shared living space.
But you need to live your life. If he can't handle that, or if you can't handle the way he handles that, you have no responsibility to be in a relationship with him. He has no right to make demands that you not be true to yourself.
Maybe your friend from online would be a better match
