A question for Conservatives

I used to call myself a Conservative. Now I just call myself Rightwing. I still vote down the line republican for SoCons or FisCons. I am an atheist and after being socially conservative on gay marriage and abortion, I’ve done a 180 degree turn on both issues. Rationally I could not find a non-religious justification for opposing gay marriage or abortion rights in at the very least first trimester.

So the question is, how is opposition to letting two loving homosexual adults get married (or even just enter into a civil union) to receive the same rights as a heterosexual couple, relevant to being a Fiscal or National Defense conservative? Where is the correlation? Same for abortion. How is supporting gay marriage and abortion (with decent restrictions), aside from also being supported by the left, prevents one from being “conservative” or on the Right on everything else? And also how is supporting gay marriage and abortion logically inconsistent with being on the Right?

Just curious.