I am more worried about his pushy
than his wanting to be open to loving others. What's that all about? It is not respectful at all!
If you do not want to be open, and want to have a sexually exclusive relationship? That is your LIMIT and it is your right to want your relationship shape to come in the shape you like it best.
Examine your limits. Are these soft limits (might change over time) or hard limits for you (never will change?)
He tells me that he won't do anything because we are not both comfortable with it yet but wants to push it on me to read books and be more open minded.
What is his motivation there? Open minded?
Or Open relationship with other lovers?
That is two different things.
Are you willing to be open to reading books and things? Being open minded to sharing in his poly inner life to listen to his talking and share in reading the things he likes to read? (It doesn't NOT have to mean you go off to having other lovers. It is allowing him SOME poly expression that you find ok to participate in and safe enough for you.) Is opening up just that far something you are willing to do? (And if you are not, that is totally ok to have that as a personal LIMIT also.) Would that satisfy his need or not? If he's not willing to keep it there, then you are best apart then since you are monoamorous AND want a monogamous relationship.
Is he trying to get you to read things to push this on you and pressure you into saying "Yes" because he's worn or eroded you down? If that is his goal then that is not kind to do! It is more respectful to accept you both want different things in life and split amicably than to be haranguing/abusing your partner to get your own way. That's bratty.
So which is it over there? What is his need and his intention there? To share his poly THOUGHTS with you or wanting to share his poly BODY with you and Another? He can offer that but it doesn't mean you want it. Where's his limit lie?
And the way he talks is just... ew. Just not respectful. You are a vagina? He's all pushing this on you even if you say "no, thanks?" What is he? A bully?
Do I try and make it work being monogamous and not trust him, or end it now before i just get hurt?
Never stay in any relationship where you do not trust. That is not emotionally safe for you. You are responsible for tending to your healths -- mental health, emotional health, physical health, and spiritual health.