It’s so different for men than for women with aveilus. Having to worry about having a minyan to be able to say kaddish is not easy. My husband had but a 6-week break between his two years of aveilus. He had to daaven the amud for those two years. It was a hard time for him making sure there was a minyan without a prior chiyuv so that he could daaven the amud each time, 3 times a day, every day except for Shabbos and YT. He really needed a break at the end.
All I can say is that I’m sorry for your losses. Hamakom yinachem eschem besoch sha’arei tzion ve’Yerushalayim ve’lo sosifu le’daava od. You should have koach to help your parents to have an aliya to very high places in olam ha’emes. While it’s hard for you, they are fortunate to have a son to say kaddish for them. My parents only had 3 daughters. My husband says that grandsons should say kaddish (daaven the amud) and not sons-in-law. He said kaddish for my parents when my son was not yet Bar Mitzvah. Now my son says it for them.
As far as Purim goes, I thought you could have the meal at home and try to limit it to a few guests, depends on what you’re accustomed to. I’m sure you asked your Rav last year.
One last idea would be to plan a small vacation for yourself (with or without family) when this year is finished. Just give yourself a little time to wind down after all of this. It’s not to celebrate, but to give you some space and time for relaxation a bit without the pressures that go along with being in aveilus.