Should I have gotten married? Feeling stuck.

I have been with my husband for 4 years (married 2). He is the only person I have ever dated/kissed/had sex with. Recently I've been having feelings for a good friend of mine who I didn't meet until after I started dating my now husband. I don't think this friend has any idea about my feelings for him. I love my husband, I really do, we get along great, he makes me laugh, and he loves me so much and treats me well. However we have semi-differing viewpoints on some major things (ie politics, religion, kids etc.). I didn't even think this was a problem to me until these recent feelings for my friend, now I'm questioning everything. My friend and I don't only agree on all the major things, we have so many small things in common as well. I can't help but think that if I had meet this friend first that he would be my husband now. But I guess my question is less about this specific guy and more generally, how do I know I married the right guy? I've never dated more than my husband and sometimes I wish I did. Even if it meant that I would end up married to him at least I would know. I wish I could have been single a few more years to try and figure everything out but now I feel stuck in this marriage (as good as it is). Am I just being an asshole and not being grateful for what I do have? How do I deal with these feelings for another man? Any help with my ramblings would be appreciated x

I don't have any children, and I'm not sure if I'll be able to. He wants kids and wants to adopt/raise them the wa he was raised which is not what I would want.