How on earth do I do the R’s in words such as "saldre"?

I always feel i need to slow down mid-word to "charge up" the "dr" sound I have so much trouble with. I understand the language but find this incapability to speak it with decent proficiency irritating.

It's like i'm saying sal -dre instead on a fluid, single word.

Any advice for improving this aspect of the "R" sound (and speaking in general) would be MASSIVELY appreciated!! Gracias!