ETA: I must have skimmed too quickly. I see that you are 21 and your child is 7? If this is true, and not a typo or a hoax, then you are more lacking in maturity and parenting skills than even this post suggests. Time for serious counseling and life skills classes.
Original response:
Sounds like you child is running the show. That needs to stop.
All kids with divorced parents get disoriented or have transition difficulties when they shuttled from one parent to the other. It disrupts everything. So you have to have a strategy for helping her reintegrate when she comes back. It can be hard if one parent badmouths the other or creates a "party time" atmosphere vs. the rules/structure of the other house, but it can happen in other families even when different parenting styles aren't at play.
The other thing they do is they say stuff to get a reaction. If your daughter says she doesn't love you, she's either annoyed with you (very different from not loving), she's getting a lot of reassurance (good) or treats (bad) as you try to bring out her of it and prove otherwise. But she's also probably getting a hurt reaction from you - and that may make her feel like she's not the only one having a tough time. But whatever the reason, she's getting a payoff from her behavior. So that is something you have to stop. You say, "I'm sorry you feel that way. I love you so much." Don't keep trying to prove it to her though by taking her out for meals or giving her some sort of bribe.
I don't know how long you've been divorced or how long you've been with your boyfriend, but if those things occurred too close together, it's extremely difficult for a child. I'm not saying to ditch the boyfriend, but you really need to downplay his involvement. You absolutely should NEVER tell her that you went on dates while she was with her father or that you did X or Y that was so much fun without her! She doesn't need to know about the parts of the relationship she doesn't see, especially the fun stuff.
Every child is jealous of the time a parent spends with someone else - even the other parent, but certainly a boyfriend, a job, a volunteer assignment, family members, etc. So don't buy into it. Stop letting her manipulate you. And don't think that you can talk her out of her feelings by reminding her of how many treats you've given her. You can, and should, reassure her that you love her, but that includes putting food on her plate and getting her to bed on time and helping with her homework and surrounding her with lots of people who love her (family friends, aunts/uncles, etc.).
After you've been divorced for a LONG time and hopefully if you've been just her mom for a year or so (without your boyfriend involved), and you've had some time for just the two of you, then you can introduce the boyfriend and go on dates without her. But if he is around all the time, she's never going to see you as a single mom - she's always going to see him as the problem, as the replacement for her father, as the reason she's missing out on something.
I think you should get some books or some family therapy about co-parenting, and how to separate your own needs (to be told you're loved by her, to have a social life) from her needs for reassurance. You can't "buy" her affection and security by taking her places. If your ex is a reasonable person and will participate, great. If neither you nor your ex are putting thoughts in her head about how the other one is a bad person or left because of another individual, excellent. If that's not the case, then you have an even more difficult road ahead of you, which makes basic family therapy more important, to develop skills in helping this child to feel secure without letting her manipulate you and demand things she's not entitled to. And since you don't know how she feels, it might be good to find out. Your post is mostly filled with justification for your own activities and explaining your own hurt feelings, rather than how to parent (from a position of strength and confidence) a child who feels this way.