JUST found out i have chlamydia. How do i tell my bf???

so a little preface .. i'm 22 (female) and recently got into a serious relationship with my boyfriend (24) we've been together almost a year now . we're in an official and exclusive relationship , boyfriend/girlfriend and all that

we've been talking about other forms of contraceptives because we both don't like the feel of condoms and we also don't like the uncertainty / anxiety of the pullout method , so i've been looking into going on the pill for birth control .

i made myself an appointment at planned parenthood for a general checkup and to inquire about how to go about going on birth control without insurance , part of when when i was there they tested me for STIs like where i pee in the cup and all that . i figure that's just part of the checkup and think nothing of it because of course i'm in an exclusive relationship and don't think i'll come up with anything .

fast forward to now , i get a call from them that i'm positive for chlamydia.

i had / have no symptoms . i've had chlamydia once before in my life when i was 18 but got treated immediately thereafter and didn't have relations with anyone again for another year .

the last person i was dating before my boyfriend had cheated on me so i left because of that . me and him weren't using protection while we were together either (i was 21 at the time)

i have NOT cheated on my boyfriend , i haven't touched anyone else besides him since we've been together

i don't even know for certain how long i've had it . i just feel so guilty and so gross thinking that i may have gotten it from my last relationship and lived this whole time , MORE THAN A YEAR carrying this disease and unknowingly gave it to my now boyfriend

i know i should have gotten tested after the last relationship but it honestly just did not even cross my mind at the time . please do not scold me for that , i'm obviously learning my lesson and dealing with the stress enough .

i have to state that i do NOT think my now boyfriend has been unfaithful . i have absolutely no reason to think he would be .

we're in a very healthy relationship and i believe 100% that i did not get it from him .

i most likely believe that i had gotten it from my last relationship .

HOW DO I BRING THIS UP TO HIM ??? i don't even know how to start this conversation with him ?? i'm so terrified that he will think i cheated on him . i love him so much and i would never in my life do anything to hurt him , and i believe he feels the same about me . i'm so incredibly anxious about this entire situation .

right now he is out of the country on a trip with his family and has no phone reception ( i know this is true bc i dropped him & his family off at the airport and everything ) so we haven't been in much contact for the past few days , he doesn't get back for another two weeks .

i plan on telling him when he gets back . i still have NO IDEA how i'm going to go about this . i could cry i just really seriously don't want this relationship to end because of this . PLEASE any advice on what i should do !!! 😓