Poland and the Czech Republic aren't Western, they're Slavic. The USSR wasn't Western, nor are the offshoots of the USSR.
East Germany stopped prosecuting against GLB in 1957, and homosexual activity was officially decriminalized in 1968. 1980s Berlin literally had state-owned (again, East German) locations that were explicitly for GLB activity.
Took a bit longer for West Germany, but acceptance happened in the 1980s and in 1990 West Germany allowed GLB to join the military.
Same-sex couples have had (most of) the same legal rights as married couples since 2001 in the combined nation, I'm pretty sure, though I could be off a year. They were also allowed to adopt pre-2010, but I can't remember when.
Acceptance isn't just marriage.
It wasn’t not really much different in the US. You just have to remember it’s a state-by-state issue for the most part. Same sex intercourse was decriminalized in Illinois in 1962. Through most of the NE, Midwest, and west coast by 1970-1980.
Median age at marriage has increased from 23 to 29 for men in my parents’ lifetime: https://images.app.goo.gl/A3SinK2HNqjM9s139
Also, it’s probably not accurate to say that America is one of the last western countries to accept LGBT people. Same sex marriage was legalized nationally around the same time in the US as in Germany and the UK. A number of western countries still don’t allow it, including Italy, Greece, Switzerland, Czech Republic, and Poland.