Am I too emotionally unstable for relationships?

Long story short: It hurts me emotionally when I catch my boyfriend staring at women in public or looking up porn etc. I feel as if it's disrespectful and he should be able to stop doing things if he values me and wants to be with me. But he acts like its perfectly okay even when it makes me cry or get upset. Should I just not be in a relationship and be single? (Im pregnant rn) or should i try to work it out? Am I asking for too much or is he in the wrong for disregarding my feelings? I feel so hurt and insecure because of this and I just feel like giving up on relationships and living on my own.