He won’t leave me alone

We work today and I thought he was cool we hooked up a few times (I regret)… & now he can’t get over me. It actually annoys tf out of me some days. I already told him we won’t work our & he’ll get all pissy and blocks me or make it obvious at work he has an issue. It gives very much beta male & turns me off even more.. I tell him we can be friends and he’ll be okay for a day but any type of attention I give to another male he gets jealous. We work at a small family business so no I cannot tell anyone and secondly my boss won’t do shit about it. If anything it’ll just bring more attention to him which he wants. It annoys me bc he tells me how he thinks about me all day everyday and sometimes I feel like he taps into my energy . This will sound crazy if your not into spirituality but there’s been a few times I wasn’t at work & I’ll have this crazy unknown anger inside me I have no idea where it’s coming from and I’ll come to work and find out he got into an argument w someone here. This has happened 3 times so far and I hate it!!!! I need advice