Old demons

I'm gradually getting back to the diamond league, after sitting on top of Plat for a few days now. And facing diamond-level players, I run into the same things again that I can't beat. Harass and cheese. I actually had 2 6/7-pools in a row one night and finally beat the second one. It did not seem easy since I lost my entire forge-gateway wall-in before finally holding it off. But I did it.

But now I'm facing my absolutely most frustrating type of loss: well executed harass. Three games in a row just now I had to deal with this and lost each. Two from zergs that rushed lings by any opening I left and one from a drop-happy terran. He had 3 dropships poking in on me from 3 different angles. I can keep up after a few harass attempts but I always just get worn down eventually. I don't know how to deal with it. I can't put pressure back on him because his base will always be locked down even though he won't have a standing army of consequence. I can't just leave units to defend or he will mass up and bust my front. Especially against zerg, I feel like it's an auto-lose if I sit in my base defending. All 3 times, I hold off a few attempts, start to lose more and more workers each time, till I know I'm way behind on eco, and I abandon all my bases and try to trade, to no avail.

Maybe I should mix in some air to give myself more mobility. Or over-produce gateways more, something I always avoid.