Conflicted

so just to preface everything- i'm in a long term relationship and honestly shit has been...not great for a while now. over a year ago he cheated on me,and i opted to forgive him since we'd been together for so long and try to work through it. we've fought almost every week since. he's bpd as well, he gets angier than anyone i've ever met. he also expects me to just take care of him, anytime i need anything from him he leaves bc he "can't deal with it rn" (did i mention we've lived together for a few years now?). anyway i've just felt extremely neglected and unloved. he's also an alcoholic which definitely doesn't help any of this.

it's sad because he used to be so amazing and now i feel like i've seen his entire decline in mental health.

so on to the issue.

i work in a shopping center with other stores. i walk past the same accessories boutique everyday to get to my car. (i pass by to and from three-door times a day to work, lunch, bank runs, home. theirs a guy who works there. when i walk through the center i have an earbud in and im typically avoiding eye contact with every other living creature as outside of my costumer service mask im very shy and social anxious. but every once in a while id catch his eye and he'd smile, so id smile back.

soon we were just smiling at each other frequently until one day he stopped me to ask "okay, you have to work here right?" and i said "oh yeah- i work down at .blank." he laughed and said "ooh i thought maybe you just really liked shopping" (and i do but besides the pt)

after that it was just smiling and one time a "goodnight" as i walked past with a coworker one evening.

today however he stopped me on my lunch, to ask me what i was going to get.

the brief conversation was nice, and it was exciting that he wanted to talk to me.

he's cute too.
one thing i'm conflicted about is if i genuinely find this guy cute (whose name i don't even know) or if im just ficked up and lonely from my shitty relationship.

but i also feel like shit about having these thoughts. i get excited to see this guy, i now look for him and stayed a few minutes late one day to figure out which car is his. but i know what it's like to be cheated on and would hate myself if i ever did anything to my partner like that. and breaking up with my partner seems difficult and maybe impossible due to his mental state, financial state and the fact that we live together.

idk if i want advice or just needed to get it off my chest? is this normal? is it okay to have a little crush?