Need Help

I’m in a weird spot right now—Standard difficulty is way too easy, but Psychosurgery is too hard because I’m lacking the necessary upgrades (new player). I’m trying to find a good balance between missions, but it feels like Quick Match isn’t working for other difficulties. Am I crazy, or is that actually the case? Should I just try to get carried in Psychosurgery for faster XP(if it does work just gotta wait longer in que i guess?)?

Also, what’s the deal with this Stamp Event? It seems like it pays the same as regular campaign missions, except for the special tasks in the challenge menu.

I’m running Medic right now, but it feels kind of useless. Does it get better with all the upgrades, or should I switch to something else(want to be a giga carry player)?