Should I stay or should I go? HELP!!

Hello everyone. I'm 28 years old & my boyfriend is 35. He has full custody of his 11 year old daughter. He & I have been on & off for almost 8 years now, the last 2 years being the most serious (even though we might have broken up for a few months in between.) We were planning our wedding for April 2018 (not actually engaged though) & have been house hunting since April.

We started seeing a therapist for pre-martial counseling recently & a lot of things came to light that I had no idea of. Apparently things weren't as good as I thought, he was just modifying his behavior to adjust to my personality. The way I am has always been a issue & instead of him suggesting ways I can change the way I am, think, feel or whatever he's always pointing out my flaws. Don't get me wrong he's a GREAT man, but after seeing the therapist one on one yesterday... I'm not sure if I'm this relationship for the right reasons. As I mentioned he has a daughter which I've had a hard time bonding with, not because she's difficult, on the contrary she's sweet, but we just don't click. As I was speaking to the therapist I caught myself making excuses for what I know is right in my heart & all she kept saying was to follow my gut. With her saying that I really felt like what she was trying to tell me was "you're not compatible, don't make this mistake." It's hard to judge a relationship from the outside I would think, but maybe she saw things that I don't when the 3 of us met. Maybe on his one on one session he said something to make her thinks this won't work out either.

I honestly don't know what to do. Her words have been marinating in my mind all day and I just keep praying to God for guidance and to make the right decisions. I know I love him, but is love enough? Is it my fear of never finding someone else with all his wonderful qualities keeping me with him? I can't force a relationship with his daughter that doesn't come natural..... I don't know what to do. Please advise :`( I feel like I'm losing myself.