My insecurities are ruining my relationship

My boyfriend and I have have been together for a year and 8 months. I am in love with him for sure but our problems are taking a toll on us both. I have caught him checking out other women while we are together in public. I used to not be upset by this but it seemed to get to me more each time he did it. I finally called him out on it and he immediately apologized and said he wouldn’t do it again. He has also lied to me many times in the past over really dumb things to protect my feelings. Because he has lied to me so many times in the past it’s very hard for me to trust him. Now i overthink every situation. We have had many talks about this topic and he says he does not want to do it anymore because he has me and “ I am enough for him “ But i still get upset/mad or accuse him. Deep down I believe he isn’t doing anything but my emotions just take over. He also doesn’t watch porn anymore, but he used to almost everyday even while we were dating. Basically what it all boils down to is that I don’t think our relationship is healthy at all, but I want to be with him more than anything in the world.