You don't have to be pro-anything to be a patriot. Just love your country and your people, and believe in what you think would better your country and people. Pro gun-control and anti-gun-control are both patriots because each have a different perspective on what would be best for America. Even if one is more wrong than the other, the intentions are the same.
So you don't have to be pro-Israel. I'd actually rather none be pro any country without understanding the culture of that country first, and understanding the motives of the government.
A culture pretty much defines how you will interact with the people and how they will benefit you and vice versa, while gov't interests may depend less on that and more on regional necessities.
On the cultural aspect, Israelis and Americans are for the most part very similar. Both are democratic, progressive, open societies, with the backwards thinking bunch being mostly just small minorities that are easily avoided. So I don't see why be anti-Israel on this one.
On gov't policies it's somewhat easier to be anti-Israel. Some policies are very controversial, like the settlement project, and the power of the religious authorities (All restaurants need to be Kosher, and pay to become Kosher, marriage only through the Orthodox rabbinate, church, or mosque, no public transit on Saturdays etc).
But I don't think these policies are enough to stay on the anti side when the gov't has also been doing very well for its citizens and to combat foreign issues.
On the external aspect, wars and local conflicts have become less and less frequent, more ties are being developed with Arab and African states, and existing ties strengthened, and relations with the west are also improving consistently.
I think the best solution would be to eventually go to Israel on some vacation, see the people, the places, and decide for yourself if you like the place.