MMR should be tweaked

I feel like MMR should reset or be boosted significantly once promoted. It's really hard to gain LP consistently especially in Diamond. For example, if your MMR is Diamond 4 and you hit Diamond 3. Your gains will be disgustingly bad and you will have to play a lot of games just to stabilize your MMR. I don't think it's fair how if your over your MMR significantly, you can have gains of +12- +18 and lose -25 to -30. This happens to me. I know that I have to do well and win more games than I should but I really don't think that I should lose double my gains just because my MMR is lower than what it should be. I have been winning a lot lately but I know that once I lose, I will lose all my hard work which really makes it terrible. I feel like I should at least lose less but also gain less. It makes it way too difficult to climb in a timely manner.

What do you guys think?