It can be a hard slog (uphill, through the mud without wellies), at times. Sometimes you have to look for the small victories, and sometimes what you come up with is "I got out of bed today!"
Let yourself feel whatever you're feeling. If it's a down day, then don't think you have to paste a fakey-fake smile on it to make other people happy...let the unhappiness wash over you and pass. If you tamp it way down, it'll just grow and spread. Feel it and then let it go, as best you can, as soon as you can. And if you fear falling into a rut of Eeyore-ish outlooks, you have friends here to give you a hug and a to help you move forward.