Insanity tips?

This is the only achievement I do not have for this game and it took me a while to want to start it because I have heard how brutal it is. I'm going for minimal completion here as this is just an achievement run. I have heard that Infiltrator is the best class because of the cloak for escaping bad situations and a cloaked sniper headshot is supposedly the highest damage output in the game. I never could find a definitive answer as to whether a ME1 import or brand new ME2 character was better than importing a ME2 character. I imported a ME2 character because I knew I would have the Widow right away. I ran into a few tough spots but eventually prevailed.

However, I am now on the Collector Ship mission and I had to take a break. I spent an hour just on the first confrontation and my average life at that part couldn't have been but like maybe 4 minutes. There is nowhere to go and only one real spot for cover for the majority of it. The only other cover that becomes available isn't far away so it doesn't help much. So far it has only delayed my inevitable death. Harbinger rushes and then stand right in front of the cover and just spams. The one attack staggers and rips me out of cover. If this coincides with a shockwave attack from one of the Scion's, it means death. My squad goes down quick. Grunt was tanking up until now, in which he goes down almost as quick as the rest. My instincts say bring a biotic with warp because Collectors have barriers, but they go down so quickly. I have the Collector Particle Beam as my heavy, that seems like the best option, it's just slow and requires being out of cover for long periods of time so maybe it's not. I've also upgraded as much as I can so far. Samara and Mordin are loyal.

For those that have beaten this, what do I need to change?

Yes, ME2 is quite rough on Insanity, certainly more so than the other two games. I'd suggest using a Sentinel since they are imo by far the best class in the game because of their powers (some prefer Vanguard and that's cool too), but as for weapons/allies and so on, I can't remember too well what I used. I never had much trouble with the collector ship due to overpowered Sentinel abilities, but you should be able to manage without that. I wouldn't use Grunt personally, rather anyone with Warp, which in this game is the best thing ever. The Particle Beam is fine for a heavy weapon though, the other choices are even slower so I wouldn't bother with them except for the Cain on the last boss.

Thanks for the tips. I'll bring two squaddies with warp and if that doesn't work it may be time to restart with a Sentinel. Which it will be awhile before I do that. I still have two runs through the trilogy in general that I want to do so I am likely to do one of those first, one of which I will make sure is a different class that I can try Insanity with.