Taurus behavior? im heartbroken

Hello everyone. Im very new to this forum, just made an account today, but have been checking this site out for years.

Im a 28 year old libra. English is not my first language, so sorry if its not correct.

I have been dating a taurus 27 year old guy for almost 3 months.
He is very sweet, affectionate, romantic, everything I would like in a man. We had only been dating for about a month, and he bought me a gift for my birthday, he also wrote a song to me about his feelings for me. Im crazy about him. But im also crazy jealous.

I have been in a couple of really bad relationships in the past, where my boyfriend cheated on me for years. So i have a hard time trusting people, my taurus guy knows this. He told me to trust him, and not doubt his feelings for me. So i tried...

2 days ago we were hanging out at his brothers house, i took his phone to search for a song, but i could resist to dobbelclick the iphone button so I could see all the open pages. I saw the message page, and some girl had texted him something and called him bubbi and put a kiss emoji. I was in chock, but i didnt say anything because i didnt want to get in a fight, but i was heart broking.. on my way home i cried all the way.

The morning after i texted him, that i saw it, and i ended it, and wished him luck. I know its dramatic but i couldnt think clear at that moment.
He texted me back saying i have misunderstood something, and that he hasnt showed me anything but loyalty, he havent felt this way for anyone in 7 years.
we texted back and forth for sometime, and he said that it was a friend and that he had helped her with something and that was her way of thanking him.
so i ofcourse said prove it.
And after that, he became different talking about i had hurt him by throwing him away by a text, he had dreams about us getting married, and he is heartbroking that i accuse him of something like this, i should have asked him about it, and he would have told me everything. but he didnt want to prove anything to me, because i had already ended it, and that he obviously didnt mean anything to me since i could do something like this to him. At the end of the text he wished me good luck with the future. we texted for sometime. and i also said that if you really do have so strong feelings for me, you would try to prove it and work it out..
in my last text i wrote, something like im sorry i didnt ask you, you mean alot to me.. I apologised ! but he didnt reply 😢

Im so heartbroken and confused.
what do you guys think? I hope to get some anwers

His chart

Sun: taurus
moon:leo
Mercury:taurus
Venus:gemini
Mars: aquarius
jupiter:taurus

My chart

rising sign: sagg
sun: libra
moon: sagg
mercury: scorpio
Venus: libra
mars: virgo

i also posted in taurus forum